COMPUTING FOR HOME AND BUSINESS
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JUNE 1980 $2.50
SMALL COMPUTERS ■
OF THE 80s mTl
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71486 02651
CANADA/MEXICO $3.00
How Do They
Stack Up?
COPS AND
COMPUTERS
21st CENTURY
SURGEONS
BIG
State of the art "Winchester"type hard disk with a data
storage capacity of nearly 16 Megabytes, makes the
SWT PC 6809 system the most flexible as well as the most
powerful eight-bit microcomputer system in the world.
The intelligent controller, using DMA data transfer, makes
maximum use of the “Winchester" capability. It is com-
pletely compatible with the FLEX9 operating system used
on the SWT PC 6809 floppy disk system.
CDS-1 "Winchester” disk drive with controller . .$3,995.00
Cabinet— matching our 6809 computer desk . . . 150.00
SOUTHWEST TECHNICAL PRODUCTS CORPORATION
219 W. RHAPSODY
SAN ANTONIO, TEXAS 78216 (512) 344-0241
CIRCLE INQUIRY NO. 56
RS-232 or
Latched
Outputs
4 MHz
Crystal Clock
On Card
Voltage
Regulation
Parallel
I/O Port #1
Parallel
I/O Port #2
8K ROM
Capacity
Parallel
I/O Port #3
\
IK RAM
Current Loop
I/O Port #4
- Standard Bus
for System
Expandability
Programmable
Baud Rate
UART with
Interval Timers
MHz Z-80A
The single card computer
with the features
that help you in real life
COMPLETE COMPUTER
In this advanced card you get a pro-
fessional quality computer that meets
today's engineering needs. And it's one
that's complete. It lets you be up and
running fast. All you need is a power
supply and your ROM software.
The computer itself is super. Fast
4 MHz operation. Capacity for 8K bytes
of ROM (uses 2716 PROMs which can
be programmed by our new 32K BYTE-
SAVER® PROM card). There's also IK of
on-board static RAM. Further, you get
straightforward interfacing through an
RS-232 serial interface with ultra-fast
speed of up to 76,800 baud — software
programmable.
Other features include 24 bits of bi-
directional parallel I/O and five on-
board programmable timers.
Add to that vectored interrupts.
ENORMOUS EXPANDABILITY
Besides all these features the Cro-
memco single card computer gives you
enormous expandability if you ever need
it. And it's easy to expand. First, you
can expand with the new Cromemco
32K BYTESAVER PROM card mentioned
above. Then there's Cromemco's broad
line of SI 00-bus-compatible memory
and I/O interface cards. Cards with fea-
tures such as relay interface, analog
interface, graphics interface, opto-
isolator input, and A/D and D/A con-
version. RAM and ROM cards, too.
Card Cage 32K BYTESAVER PROM card
EASY TO USE
Another convenience that makes the
Model SCC computer easy to use is our
Z-80 monitor and 3K Control BASIC (in
two ROMs). With this optional software
you're ready to go. The monitor gives
you 12 commands. The BASIC, with 36
commands/functions, will directly ac-
cess I/O ports and memory locations —
and call machine language subroutines.
Finally, to simplify things to the ulti-
mate, we even have convenient card
cages. Rugged card cages. They hold
cards firmly. No jiggling out of sockets.
AVAILABLE NOW/LOW PRICE
The Model SCC is available now at a
low price of only $450 burned-in and
tested (32K BYTESAVER only $295).
So act today. Get this high-capability
computer working for you right away.
Cromemco
incorporated
Specialists in computers and peripherals
280 BERNARDO AVE., MOUNTAIN VIEW, CA 94040 • (415) 964-7400
CIRCLE INQUIRY NO. 16
JUNE 1980
VOL. 5, ISSUE 6
SINCE DECEMBER 1975
Comparison Charts .... Pg. 80
Looking at Micros Pg. 70
Dust Writer Pg. 66
COMPUTING FOR HOME AND BUSINESS APPLICATIONS
GENERAL FEATURES
The Dust Writer 66
by Michael J. Hodgetts
Comparison Charts Explained 80
by Tom Fox
BUSINESS FEATURES
Looking at Micro-Based Business Systems 70
by Tom Fox
HARDWARE FEATURES
Teach Your PET to Read “Marked Cards” 56
by Marvin Mallon
System of the Month: The Escon Selectric Interface 62
by Hampton C. Miller and Andrew Klossner
Mixed Interfaces 108
by Richard A. Leary
An Error Correcting Memory 114
by Terry Dollhoff
Lazor: The Business “Dream” Machine 122
by David R. Fuller and Harold Henrich, Lazor Systems. Inc.
LEARNING CENTER
The Teacher and the Personal Computer: Alternatives in Instruction 89
by Samuel W. Spero
My TRS-80 Likes Me 94
by Bob Albrecht
MATHTEST 96
by Bethany Prendergast
Using and Building Micro-Based Systems 98
by David Marca. Associate Editor
SOFTWARE FEATURES '
Assignment: Benchmark 130
by Tom Fox
A Break Service Routine for a KIM-1 with a Teletype .132
by Ken Wetzel
Textwriter: An 8080/Z-80 Text Output Formatter 136
by Alan R. Miller
FREE RUNNING
Editor’s Notebook 4
Letters to the Editor 10
The Column 17
Jurisprudent Computerist 28
Al Baker’s Game Corner 30
Micro Mathematician 36
Mind Revolution 46
Business Software Review 48
Inventor’s Sketchpad 50
DEPARTMENTS
Update 18
Calendar 22
Book Reviews 24
New Products 118
Micro Market 142
Microdex 143
Advertiser Index 144
INTERFACE AGE Magazine, published monthly by McPheters. Wolfe & Jones, 16704 Marquardt Ave., Cerritos, CA
90701. Subscription rates: U.S. $18.00, Canada/Mexico $20.00, all other countries $28.00. Make checks payable in
U.S. funds drawn on a U.S. bank. Opinions expressed in by-lined articles do not necessarily reflect the opinion of this
magazine or the publisher. Mention of products by trade name in editorial material or advertisements contained herein in
no way constitutes endorsement of the product or products by this magazine or the publisher. Circulation Department,
(213) 926-9540.
INTERFACE AGE Magazine COPYRIGHT © 1979 by INTERFACE AGE Inc. ALL RIGHTS RESERVED. Material in
this publication may not be reproduced in any form without permission. Requests for permission should be directed to
Nancy Jones, Rights and Permission, McPheters, Wolfe & Jones, 16704 Marquardt Ave., Cerritos, CA 90701 .
INTERFACE AGE Magazine is catalogued in the Library of Congress, Classification No. QA75.5.155. USPS No.
528150. ISSN Publication No. 0147-2992. Membership in Audit Bureau of Circulations applied for.
POSTMASTER: Please send change of address form 3579 and undelivered copies to INTERFACE AGE Magazine,
16704 Marquardt Ave., Cerritos, CA 90701. Controlled circulation postage paid at Olive Branch, Mississippi and
Artesia, California.
The place to buy
Cromemco Systems
or North Star Systems . . .
or Vector Graphic Systems . . .
or Dynabyte, Micromation, et. al.
'erminals. Printers, Disks, or Software — Literally any
Cromemco system. Board, or Software package can be
DELIVERED FROM STOCK at the lowest prices!
Cromemco Z-2H
Full 11 -megabyte Hard Disk System!
List
$9995
OUR PRICE
$8489
e Full 11 -megabyte hard disk system • Fast
Z-80A 4 MHz processor • Two Floppy Disk Drives
• 64K RAM Memory • RS232 Special Interface
• Printer Interface and • Extensive Software
Available.
Cromemco HDD
11/22 megabyte Hard Disk for use with existing
systems. DMA controller. Transfer rate of 5.6
megabytes/second.
System 3
- NOW DOUBLE THE CAPACITY -
with 64K of RAM
List
$6990
OUR PRICE
$5890
Cromemco System 2
Now features dual-sided drives — double the capacity. Similar
to System 3, except features dual, double-sided mini floppy
disk drives. List $3990 Q |^| |_y $3390
Z-2 Computer System (can be rack mounted)
List $995 OUR PRICE $845
Single Card Computer — SCC-W,4mhz
List $450 OUR PRICE $382
HDD-11, List $6995. .
HDD-22, List $11,995
our price $5,939
$10,189
NEW Color Graphics Interface — SDI
List $595 OUR PRICE $505
SHIPPING AND INSURANCE: Hard Disk Systems, System 3, and System 2 shipped freight collect. For boards, add $2.50.
All prices subject to change and all offers subject to withdrawal without notice.
- WRITE FOR FREE CATALOG - CIRCLE INQUIRY NO. 80
vm
MiniMicroMart, Inc.
1618 James Street, Syracuse NY 13208 (315) 422-4467 twx 710-541-0431
EDiTun'5 iuuTEBuuiri
When this issue goes to print, we will be
starting at the midpoint of 1 980. And where
are we? As of this writing, we are facing
record inflation, insane interest rates, a battle
for the presidency and ever-increasing
economic pressure that threatens several
key segments of our economy.
One of the segments that is undoubtedly
under some of the greatest pressure certainly
has to be the small businessman. I’d like to ad-
dress some of the challenges that are facing this
very important part of our nation’s foundation.
As we see the economic noose tightening
on the small businessman, several things
are going to begin happening— and it will
not require a soothsayer to predict the
occurrences. Undoubtedly, we will see more
and more small businesses failing. After all,
some 70 to 80% of all new small busi-
nesses fail in their first five years even when
the economy is relatively stable. Surely
the small business failure rate will con-
tinue to climb.
We will probably see fewer new stores,
shops and businesses sprout into being, as
the cost of seed money is entirely unreason-
able. One of the realities of life is that it gen-
erally takes money to make money, and if
the budding entrepreneur has to borrow
money at prohibitive interest rates, then the
cost of money alone will probably sound the
death bell over new business.
But don’t get me wrong, I’m not mourn-
ing the demise of the small businessman.
On the contrary— the typical small business-
man or entrepreneur is no slouch. These are
people who are dedicated to the success of
their venture, people who are not afraid to
take a risk, people who will be more than
willing to turn to technology for assistance in
meeting the challenges of small business.
Many of these people will turn to the
micro-based small business system, hoping
to use the “electronic brain” of the 1980s
to their economic advantage.
A number of small businesses will suc-
ceed in the marriage of small business and
the micro. After all, one of the reasons for
the booming success of the small system is
that it is an extremely powerful tool for small
business and the cost is not necessarily pro-
hibitive.
But what of those businessmen who are
unsuccessful in their implementation of the
micro-based system? Does their failure to
implant high technology within their
business reflect only an individual failure, or
is it a failure of our industry to provide a
“universal” enough machine for every
business, every situation, every application
and every individual? I suspect that it is
neither, for there are few simplistic answers
for multi-faceted problems.
One of the causes that we will be examin-
ing in future issues has to do with planning.
The fact of the matter is that many of the
planning activities that are essential for the
successful operation of the largest computer
centers are just as necessary for the small
businessman. In fact, some of the planning
is even more critical for small businesses be-
cause of the general lack of a broad financial
base within individual businesses.
For despite wishes to the contrary, the in-
stallation and implementation of a computer
system within the small business framework
is not a “plug and go” situation. While
technology of 1980 can be a Godsend to
the small business, it can also be a disaster
of the gravest proportions if a system is ill-
conceived and poorly planned.
Specifically, we are going to start examin-
ing the roles of education, backup, disaster
planning, pre-purchase evaluations, systems
analysis, ethics, privacy and many other
issues. We will be looking at how these
issues can and do impact small businesses
and how the users of micro-based systems
can benefit greatly from the trials and errors
that large systems users have been dealing
with for many years now.
TRS-80 OWNERS
— here’s your
investment management program
This is the program TRS-80 owners have been
waiting tor! Investment Portfolio Systems
(IPS) was developed by security analysts
working with software designers. It is a
powerful program that comes in one cassette
— 16 K Level II Basic on one side, 32 K Disc
Basic on the other.
Now, your computer can give you the help you
need for better investment management:
• Store and report data on your full portfolio.
• Review your securities by purchase price,
yield, % gain and loss.
• Provides four special reports:
—Status: Purchase date, No. of shares,
Purchase date values for: price, P-E,
Selected Market Index: Current values
for dollar yield, price, P-E.
—Value: No. of shares, total purchase
price, current market value, total $
return, % of portfolio for each security,
portfolio totals.
—Gain: Long and short term gain/loss,
days to long term, % gain or loss since
purchase, change in market index in same
period, portfolio totals.
—Security Analysis: Earnings per share,
% change in earnings. Annualized
change in earnings. Market Index, gain/
loss; and % yield. Plus, an ROI factor to
correlate with inflation and other indices.
— “What If’: The program lets you
compare alternatives in terms of ROI.
It’s all yours for just $49.95 ... The Invest-
ment Portfolio System program in cassette, a
32 page booklet with instructions, documen-
tation, and the program listing. Or send for the
booklet alone for $7.95, $5.00 of which will
be refunded if you buy the cassette in 30 days.
Personal Finance Systems 1446 Durham Road Dept. I Madison, CT 06443
To: Personal Finance Systems:
Please send me the material indicated below. I understand that the program requires 16
K Level II TRS-80 for tape; 32 K Level II TRS-80 with 1 disk drive for Disk.
( ) Investment Portfolio System Programs & Documentation @ $49.95
( ) Investment Portfolio System Documentation @ $7.95
My check enclosed for total ( ) Master Charge Account #
amount of $_ ( ) Visa Bank#
Expiration date
Telephone Orders accepted with Master Charge or Visa. Call (203) 421-3379
Name
Address
City_
.State
-ZiP-
TRS-80 is a registered trademark of The Tandy Corp.
PERSONAL FINANCE SYSTEMS
^ 1446 Durham Road • Madison, CT 06443
4 INTERFACE AGE
CIRCLE INQUIRY NO. 51
JUNE 1980
Solve your personal energy crisis.
Let VisiCalc Software do the work.
With a calculator^ pencil and paper you can spend hours plan-
ning, projecting, writing, estimating, calculating, revising, erasing
and recalculating as you work toward a decision.
Or with the Personal Software VisiCalc program and your
Apple* II you can explore many more options with a fraction of
the time and effort you've spent before.
VisiCalc is a new breed of problem-solving software. Unlike
prepackaged software that forces you into a computerized
straight jacket, VisiCalc adapts itself to any numerical problem
you have. You enter numbers, alphabetic titles and formulas on
your keyboard. VisiCalc organizes and displays this infor-
mation on the screen. You don't have to spend your time
programming.
Your energy is better spent using the results than get-
ting them.
Say you're a business manager and want to project
your annual sales. Using the calculator, pencil and paper
method, you'd lay out 12 months across a sheet
and fill in lines and columns of figures on
products, outlets, salespeople, etc. You'd cal-
culate by hand the subtotals and summary
figures. Then you'd start revising, erasing
and recalculating. With VisiCalc, you simply
fill in the same figures on an electronic
"sheet of paper" and let the computer do
the work.
Once your first projection is complete,
you're ready to use VisiCalc's unique,
powerful recalculation feature. It lets you
ask "What if?7 examining new options
and planning for contingencies. "What if"
sales drop 20 percent in March? Just type in
the sales figure. VisiCalc instantly updates
all other figures affected by March sales.
Or say you're an engineer working on a design problem and are
wondering "What if that oscillation were damped by another 10
percent?" Or you're working on your family's expenses and
wonder "What will happen to our entertainment budget if the
heating bill goes up 15 percent this winter?" VisiCalc responds
instantly to show you all the consequences of any change.
Once you see VisiCalc in action, you'll think of many more
uses for its power. Ask your dealer for a demonstration and dis-
cover how VisiCalc can help you in your professional work and
personal life.
You might find that VisiCalc alone is reason enough to
own a personal computer.
VisiCalc is available now for Apple II computers with
versions for other personal computers coming soon. The
Apple II version requires a 32k disk system.
For the name and address of your nearest VisiCalc
dealer, call (408) 745-7841 or write to Personal Software, Inc.,
592 Weddell Dr., Sunnyvale, CA 94086. If your
favorite dealer doesn't already carry Personal
Software products, ask him to give us
a call.
CIRCLE INQUIRY NO. 52
VisiCalc was developed exclusively for
Personal Software by Software Arts, Inc.,
Cambridge, Mass.
TM— VisiCalc is a trademark of
Personal Software, Inc.
Apple is a registered trademark
of Apple Computer, Inc.
CLiiuria luuictiuun
The additional attention that we will
be giving to the use of the micro in small
business does not represent a departure
from the present editorial direction of
INTERFACE AGE, instead, we view it as
an extension of the existing direction.
We have no intention of ignoring the
needs of those readers who are not in-
volved in small businesses. We intend to
continue our coverage of all the diverse
aspects that make microcomputer use in-
teresting, challenging and fun.
I encourage those readers whose primary
interest is in the personal computing arena
to pay some heed to this upcoming cover-
age. This subject area will be of interest to a
broad cross-section of our readership.
Getting back to the small businessman for
a second, there is a way in which you can
help us to write about the issues and con-
cerns that impact you the most— drop us a
line. Communication is a two-way street.
We encourage you to write and tell us what
you think we should be covering. Our
publication is only as good as our readers,
and we are keenly interested in writing about
the subjects that interest you the most, not
just the subjects that happen to tickle our
fancies.
Of course, there is no guarantee that we
are going to jump at a suggested subject in
search of a story— but your comments and
suggestions can play a vital role in helping
us shape editorial direction. Write INTER-
FACE AGE, Editor’s Notebook, P.O. Box
1234, Cerritos, CA 90701. □
There’s something at Rainbow for every Apple II® owner. From
software and hardware to accessories and services. We’re your
one-stop center for everything you need for your Apple II® computer
— for your business or your home.
An innovative portable power
system for your Apple II. ® You only
— > batter *
f>°
need to supply a 12V auto battery for operation
anywhere in the world. Now, you can run your
Apple II® in a car, van or boat. Developed by Rain-
bow, Powermaster is a complete power supply
system that supplies all voltages with enough
reserve capacity to drive all peripheral slots
(including a floppy disk controller). Adding an
AC/ DC TV gives you a complete stand-alone sys-
tem that will run anywhere. Powermaster simply
plugs into the Apple II " motherboard, providing
uninterruptible power for the most critical applica-
tions. Battery charging and recharging is easily
accomplished with a standard trickle charger, auto
alternator, or solar panel. Powermaster does not
use the Apple power supply. . . $495.00
(12V auto battery, charger, AC I DC TV not included)
\\e«
W
jl. This digitizer drawing board,
complete with a powerful software
ie on disk, lets you create any picture in
%!■ i + i/*\r-i nr<!mkir»o U’e irlnol
jl. * Here’s a professional word proc-
essing system that lets you edit, move,
delete, find, change, and repeat any body of
text, merge and save on disk. Does right-justific
margins, centering, page numbering. Enter name
and address on form letters when printing. Edit
and merge any text file — even those not created
by WRITE-ON— and spool to disk for letter print-
ing or editing. Chain up to 100 files in a single
printer run. Needs Applesoft and 32K $99.50
-te* otv "
. Includes all the features of
WRITE-ON I plus a data file merging
system that can output a personalized form
letter, check or document for any/all names on a
mailing list. Create and maintain mailing lists or
other data files, or produce mailing labels. Its pre-
formatted files speed up output on unbuffered or
ultra hi-speed printers $150.00
color with high resolution graphics. It s ideal for
complicated graphics. Color, edit, save and recall
what you draw. A simple-to-use system for artists,
students, engineers and graphic programmers.
Has an QW x 11" working area. Expanded features
include: Text Writer — adds words to your pictures.
You control size, color and direction of text; Elec-
tronic Drawing lets you create schematics and
includes commonly used symbols for transistors,
OP AMPS, FETS, and more; Distance! Area — lets
you compute distances on maps and/or area of
any figure.
Applesoft and 32K required $249.95
On Powermaster and Versawriter II orders, add $5
(U.S.) or $10 (foreign) for handling and shipping
A powerful file manager that
gives you two programs— FORMAT
RETRIEVAL. It handles everything from phone
FORMAT and
lists to legal abstracts. Design your own data
structure with up to 500 characters per record and
up to 15 searchable fields in any combination.
Needs 32K. On disk $49.95
. y\X^ Has all the same features as
Filemaster I plus allows for tallying,
totaling, advanced math routines, more power-
ful print formatting, larger data fields, and disk-
to-disk transfers $99.50
Needs 48K and Applesoft ROM.
+ = Apple Plus compatible
On software orders, add $2.00 (U.S.) or $5.00
(foreign) for handling and shipping. California res-
idents add 6% sales tax. VISA ! BANKAMERIC ARD
and MASTERCHARGE accepted. No shipments
made to PO boxes.
RAINBOW COMPUTING INC.
msm amansnaj
Garden Plaza Shopping Center
9719 Reseda Boulevard
Northridge, CA 91324
213/349-5560
COMING
NEXT
MONTH
INTERFACE AGE exam-
ines a unique microcom-
puter application that
monitors and controls a
household solar collector.
In addition, those with con-
ventional heating devices
will learn how to apply this
system to their individual
needs.
Remote control is dis-
cussed as a way to give a
system maximum control
over home or business
functions.
A new series on compu-
ters in education will be in-
troduced as INTERFACE
AGE explores the expand-
ing role of computers in
the classroom.
The July issue also fea-
tures the monthly software,
business and hardware
stories, columns and tutor-
ials. But that isn’t all; a
special new products direc-
tory is offered, listing over
250 products, making this
a valuable and highly infor-
mative issue.
6 INTERFACE ACE
JUNE 1980
One company
has sola
more printers
to this planet
than anybody.
Epson.
Surprised? You shouldn't be. Because we've man-
ufactured over half the print mechanisms in exis-
tence on this planet. And we've sold more of them
than all the others — combined. Now that's the
kind of experience you can count on.
But maybe you haven't heard of us. And that's
understandable. You see, for years, different
companies have marketed the lion's share of our
print mechanisms for hundreds of applications in
dozens of markets. Our products, their names.
Now we're changing that: our product, our name.
We'll tell you right
now that we intend to be as
big in printers for personal
computers as we are in
printers for the rest of the
world. And we intend to get
there the same way. By mak-
ing printers you can count
on to perform. With the op-
tions and interfaces you need. And by deliver-
ing what we promise. When we promise it.
The funny thing is that we never set out
to be the biggest printer company in the world
— only the best. And we didn't get here by
turning out inferior products or charging an
arm and a leg. We got here by turning out qual-
ity mechanisms at the rate of one for every
second of every working day. So we can sell each
one for a little less.
You'll find Epson in better computer stores
everywhere. Look for us.
Because even if you haven't
heard of us up to now,
you'll be hearing a lot
more of us from now on.
EPSON
EPSON AMERICA, INC.
Western: 23844 Hawthorne Boulevard, Torrance, California 90505 • (213) 378-2220 TWX: 910-344-7390
Eastern: 98 Cutter Mill Road, Rm. 350, Great Neck, New York 11021 • (516) 487-0660
JUNE 1980
CIRCLE INQUIRY NO. 27
INTERFACE AGE 7
DISC SVSTCM
SUPER
PRICE/PERFORMANCE
■ Complete Sub-System: DRIVE, CONTROLLER, and CABLES for S100
computers ■ Uses the most popular drive for small business systems
■ 10 Megabyte formatted capacity ■ 5MB fixed platter plus ■ 5MB 5440
removable cartridge for FAST BACK-UP and UNLIMITED off line STORAGE
■ Look Ahead buffer for maximum performance ■ expandable to 40 MB
■ Supported by CP/M 2.0,® MP/M ,® Oasis, Famos, Fordos, Tempos
Operating Systems ■ Beautiful teak finish table top (shown) enhances any
office decor ■ Rack mount also available ■ Dealers/OEMs contact John
Costello.
XCOMP, INC., 99 15- A Businesspark Ave., San Diego, CA 92131 • (714) 271-8730
XCOMP
CIRCLE INQUIRY NO. 71
tt-JOZ:
Swingline 6300
Table -Top Decollator
SWINGLINES DECOLLATOR
SEPARATES FORMS FAST
EASY. CLEAN.
isMsrysfJjr*?*’
f CCJMPA/VY
The Swingline Company
A Division of Swingline Inc., Dept.
32-00 Skillman Avenue. L.I.C., N.Y
Why mess with taking apart forms?
Our table-top Decollator separates carbon and
carbonless continuous forms quickly and
easily. Stacks ’em up nice and neat with no
carbon mess. It’s easy to load, no special
set up or operating
skills needed. >•
There’s even a 1 '
variable speed
control. Made
in U.S.A.
iiuTEnraLC d5E
16704 Marquardt, Cerritos, CA 90701
(213) 926-9544
TWX (910) 583-1412
PUBLISHERS
PUBLISHER/EDITOR-IN-CHIEF ROBERT S. JONES
EXECUTIVE PUBLISHER NANCY A. JONES
ADMINISTRATION
PUBLICATION DIRECTOR MIKE ANTICH
PUBLICATION ASSISTANTS DORIS RIOPEL
CHERYL JOHNSTON
ACCOUNTING SUPERVISOR KAY SOTO
ACCOUNTING ASSISTANTS MARY ANN LOWER
SHIRLEY MAZENKO
CIRCULATION
CIRCULATION MANAGER ED UECKER
CIRCULATION SECRETARY JEANNE ADDINGTON
CIRCULATION ASSISTANT CHARLOTTE SEV'EDGE
EDITORIAL
EDITOR MICHAEL PANCHAK
ASSISTANT EDITORS KATHY TEKAWA
LES SPINDLE
SENIOR EDITOR SOUTHEAST REGION BILL TURNER
SYSTEMS EDITOR TOM FOX
SOFTWARE EDITOR ALAN R. MILLER. PhD
ASSOCIATE EDTIORS HENRY DAVIS, AL BAKER
CONTRIBUTING EDITORS R. W. BEMER
ROGER C. GARRETT
Editorial Correspondence
Direct all correspondence to the appropriate editor at: INTER-
FACE AGE Magazine. P.O. Box 1234, Cerritos, CA 90701.
PRODUCTION
PRODUCTION MANAGER TERRI LEDESMA
ART DIRECTOR FINO ORTIZ
ARTIST SAMANTHA LEE
TYPOGRAPHER MELODY A. MARTENS
ADVERTISING
NEW ENGLAND REGION DICK GREEN
7 Lincoln St.. Wakefield, MA 01880 (617) 245-9105
EASTERN REGION JOHN SENSENSTEIN
20 Community PI.. Ste. 140. Morristown, NJ 07960
(201)267-3032
SOUTHEAST REGION HARRY DILL
3938 Sussex Avenue, Charlotte. NC 28210 (704) 552-1004
MIDWEST REGION AL GRAVENHORST
STEVE SKINNER
5901 N. Cicero Ave.. Chicago. IL 60646 (312) 545-8621
WESTERN REGION BRUCE BERKEY
ZACH BOVINETTE
P.O. Box 4566. Pasadena. CA 91 106 (213) 795-7002
JAPAN TOMOYUKI INATSUKI
Trade Media Japan Inc., R. 212 Azabu Hts., 1-5-10.
Roppongi, Minato-ku, Tokyo 106
Telephone: (03) 585-0581 Telex: J28208
INTERFACE AGE EUROPE
DIRECTOR. EUROPEAN OPERATIONS H.L. GROHMANN
Dahlienstr. 4, D-801 1 Munchen-Vaterstetten
Wesl Germany
Telephone: 08106/7396
INTERNATIONAL NEWSSTAND
DISTRIBUTION
LEW ULLIAN
Orberstrasse 38, D-6000 Frankfurt/M. 61, West Germany
Telephone: (0611) 44 77 90/41 84 80
INTERNATIONAL/DOMESTIC
RETAIL CIRCULATION
MARY ANN LOWER (213) 926-9544
MEMBER OF THE WESTERN
PUBLICATIONS ASSOCIATION
AMERICAN SOCIETY OF
BUSINESS PRESS EDITORS
8 INTERFACE AGE
CIRCLE INQUIRY NO. 63
JUNE 1980
The only computer with color,
sound, user programmability
and expandability at $599.
is also expandable. Just add our
"Building Block", an optional, four-
port expansion device, and you
can hook up a printer, telephone
modem, and additional memory
cartridge or mini-floppy disk drive.
For the name of your nearest
Imagination Machine dealer call,
TOLL FREE: 1-800-223-1264. (New
York residents call: (212) 758-7550)
or write: APF Electronics, Inc. 444
Madison Avenue, N.Y., N.Y. 10022.
$599. Manufacturer's suggested retail price.
HlF^F-electronics inc.
The Imagination Machine offers
more at its price than any other
personal computer on the market
today.
Consider these features: 9K RAM,
with 14K BASIC in ROM,53-key
typewriter keyboard. A fine resolu-
tion picture, generated on your
television set or monitor in 8 colors!
A built-in, dual- track cassette tape
deck with 1500 baud rate, for APF's
digitally recorded, “saturated','
tape programs. A built-in sound
synthesizer. And two, built-in,
game style controllers, with
joysticks and numeric keypads.
When you want to go beyond
APF's library of educational, home-
and-personal management or
entertainment programs . . . when
you want to create your own pro-
grams. . .you can. The Imagination
Machine is programmable In
BASIC and 6800 machine lan-
guage. The Imagination Machine
CIRCLE INQUIRY NO. 2
"YOUR LIFE WILL NEVER BE THE SAME'
w
See us at
NCC Booth 85
DESKS
AND
STUFF
Computer terminals, business systems,
lab components . . . they all need desks
and enclosures. That’s what we’re all
about. Computer Furniture and Acces-
sories offers a standard line of furniture
suitable for a wide variety of applica-
tions. Handsome, rugged, economical
furniture in all shapes, sizes and colors.
Basic models shipped from stock in
days, not months. And we’re nice people
to deal with. What more could you
ask for?
CF*A
lc i i tro
PEEVED BUYER
I would be interested in reading an article
in your magazine telling the businessman
how to obtain a microcomputer. I’m not
speaking of applications of various types of
software; I’m speaking about just the simple
acquisition of one.
I have been trying to acquire a system for
use in my business since last July. On five
occasions, either I or my secretary have
gone to Radio Shack or Apple stores by
appointment to observe a demonstration.
The sales people twice failed to be in the
store. At no time were we ever given a
demonstration. One Apple salesperson did
show me a beautiful printed circuit board. I
truly fail to understand why I am having
such a difficult time spending a minimum of
$5,000.
It is obvious to me why IBM is the leader
in its field; only IBM has bothered to phone
me numerous times and tried to sell me a
$22,000 system. When IBM produces a
unit for less than $10,000 we will witness
the immediate death of all other micro-
computer manufacturers, especially Radio
Shack and Apple.
David Dominick
Orange, CA
CPU PROBLEMS CITED
Regarding your January Inventor’s
Sketchpad by Roger Garrett, multiprocess-
ing seems to be the way of the future, but
Mr. Garrett soft-pedals the real problems of
multiprocessing:
1 . Complexity of operating system and
monitor software are increased. In con-
flict are desires for shared resources to
be fully used, and that contention be
avoided. The question becomes one of
serialization of activity vs. courting
either “deadly embrace” lockups. or a
lack of integrity.
2. The “nearly double” power from two
CPU-multiprocessing is substantially
worse than that, and returns diminish
for each CPU added.
3. Reliability decreases; simply, there are
more interdependent parts to fail. Should
one CPU fail holding locks for serializa-
tion, the other processors face eventual
lockout, unless some very delicate re-
covery is performed. Additionally, physi-
cal and electronic interdependencies
may cause one CPU’s ills to become
system ills, or for the whole machine to
be taken for maintenance.
Darrell Jones
Eugene, OR
ON NEW PROM APPLICATIONS
Computer Furniture and
Accessories, Inc.
1441 West 132nd Street
Gardena, CA 90249
(213) 327-7710
The article, ‘Powered Down Bipolar
PROMs’ in your April issue struck a reso-
nant chord, so I did a little research and
found a similar idea in National’s Memory
Data Book- 1977. The Data Book should
be consulted for additional information on
this very useful concept. The information
was for 74S287 PROMs, but I plan on in-
corporating the idea using 74S472s (512 x
8 in a 20 pin package); they make excellent
patches for the MCM66714 character
generator.
For those who hate discrete components,
the SN75327 by Texas Instruments comes
in a 1 6 pin DIP package, contains four in-
dependent switches, each capable of sourc-
ing up to 600 mA and provides switching
times of 30 ns as well as a common strobe
input. A dual PNP driver will fit on a 1 6 pin
header plug, whereas the 75327 provides
twice as many switches. Two may be used, if
preceded with inverters, as direct
replacements for the eight Power Switchers
needed to program the 93448.
Many thanks for the hardware article; it
saves me almost 2 watts of power.
Gerald R. Pomraning
Wilder, ID
CROMEMCO’S SUPERDAZZLER
Thank you for Tom Fox’s informative and
exciting article on Cromemco’s Super-
dazzler. I have some uncertainties regarding
memory access and allocation:
1 . Is it correct to say that the Superdazzler
cannot operate without some form of
direct memory access?
2. If the Superdazzler is hooked up with
DMA, but without two-port RAMs, and
if there is plenty of computer memory
(e.g., more than 64K), is it correct to say
that the main deficiency is the relative
overload of the S-100 bus so that the
program complexity is reduced and exe-
cution time is increased?
3. If the Superdazzler is hooked up with
DMA and with 48K of 2-port RAM
memory, does it still require 48K of
RAM picture memory in the computer
(in addition to at least 12K of program
memory), or does the computer memory
now require only program memory
(e.g. 12K or more)?
4. Why does the DMA board have to be
connected with computer memory at all?
I assume this connection is needed for
program operation. But, could the pro-
gram memory in the computer be con-
nected to the SDI via its video board?
Then, the DMA could be connected to
its own picture memory RAM without
interference with S-100 bus or computer
memory. I assume, however, that the
“picture memory” RAM might require
input from an I/O port. Could this be
done via a 2-port picture memory RAM,
^gain leaving the computer memory
free for programming?
I suppose my distinction between picture
memory and program memory is somewhat
artificial, but it would be instructive for me to
know where it breaks down.
5. What is Cromemco’s memory mapping
scheme allowing several banks of 64K
memory to be contained in the compu-
ter? Is this related to Cromemco’s 64K
10 INTERFACE AGE
CIRCLE INQUIRY NO. 11
JUNE 1980
“NTRODUCING IK HOTTEST DM Off THE
DRAWMG BOARDS: A COMPUTER TRIO THAI
TAKES YOU FROM SMALL TO KT^*.***
If you’re considering your first computing system, you need
to know more than what it will do for you today. You need to know
what it will do tomorrow.
Many businesses outgrow their first computer within a year
or two. And when they do, they find their system is difficult if not
impossible to add onto-because adding on requires a different
manufacturer’s equipment, different operating system, different
programming languages.
At ADDS, we’ve just solved this problem with Multivision, a
compact trio of stacking computers with ADDS’ CP/M® -compati-
ble, multi-user operating system. You can begin with one and
expand as needed.
MULTIVISION 1 (top module) is a get-started computer
with 5 MHz processor, 64K bytes of RAM (Random Access
Memory) and floppy-disk storage capacity of 700K bytes. It’s
available with a wide range of business application software. We
even offer our own word processing package. A fully loaded
Multivision 1 is list-priced at $3,785 without terminal.
MULTIVISION 2 (top and bottom modules) uses the new
Winchester technology to provide 5M or 10M additional bytes of
hard-disk storage. List-priced at $7,995 for 5M bytes of disk, it is
thousands less than other hard-disk systems.
MULTIVISION 3 (entire stack) turns your computer into a
multi-user system with up to 256K bytes of RAM that supports
up to four display terminals. It allows four different parts of your
business-i.e., accounting, marketing, purchasing, and shipping—
to share data and simultaneously use the system. No other
microsystem offers so much for so little.
Before you decide upon any small computer, look into
ADDS Multivision. For years we’ve been the largest supplier of
display terminals to computer giants.
Now we’re making a system for you.
For information, write: Systems Division, Applied Digital
Data Systems Inc., 100 Marcus Boulevard, Hauppauge, N.Y.
11787 Dealer inquiries invited.
CP/M is a registered trademark of Digital Research, Inc.
Applied Qgtal Data Systems Inc
SOMETHING EXTRA ll\l
EVERYTHING WE DO
JUNE 1980
CIRCLE INQUIRY NO. 5
INTERFACE AGE 1 1
Save!
BANTAM 550
From PERKIN ELMER
List $996
OUR
PRICE
$799
Add $20 for
anti-glare
CRT
Small in size, light in weight, and low in price —
but on top of the list in features and perfor-
mance.
• Upper and lower case
• Full 24 x 80 format
• Sharp 7 x 10 dot matrix
OTHER VIDEO TERMINALS
TELEVIDEO TVI-912 $789
INTERTUBE II, List $995 ONLY $799
SOROC 120, List $995 SPECIAL $729
PRINTERS
ANADEX 80-col. dot matrix, . SPECIAL $749
PAPER TIGER IDS 440, List $995 $895
w/graphics op., incl. buffer, $1194 .... $989
CENTRONICS
730-1 parallel interface, $995 NEW LOW $779
779-1, Friction Feed, List $1245 949
779-2 w/Tractor, List $1350 1049
702/2 w/Tractor, VFU, List $2480 1995
703- 2 w/Tractor, VFU, List $2975 2395
704- 2 w/Tractor, List $2350 1995
COMPRINT 912 w/parallel interf $559
912 w /serial interface. List $699 589
T.l. 810 Basic Unit, List $1895 1695
810 w/full u/lc ASCII, Vertical
Forms Control, Compressed Print .... $1895
T.l. 825, List $1695 $1395
OKIDATA MICROLINE 80, List $949 .... $799
Tractor Feed Option 109
CONVERT YOUR SELECTRIC
TO A COMPUTER PRINTER!
Power supply & electronics, A&T. You make
only a simple solenoid installation (or have
the factory do it). Manufactured by ESCON.
S-1 00 Interface Version, List $496 . $445
Universal Types:
Parallel — (Centronics format, for TRS-80,
Sorcerer, Apple, etc.) , List $575 . . $514
RS232 Standard Serial, List $599 . . 534
IEEE-488 (for PET), List $660 .... 584
TRS-80 Cable 25
Shipping not included with above prices.
All prices subject to change and all offers sub-
ject to withdrawal without notice.
write for free catalog
MiniMicroMart
1618 James St., Syracuse NY 1320.'
(31 5) 422-4467 TWX 710-541-0431
CIRCLE INQUIRY NO. 81
LETTERS
RAM card with extended bank select
(Model 64 KZ)? If so, what is bank
selection?
I would appreciate any advice or refer-
ences you can give me.
John Silver
New York, NY
/. Although Cromemco’s SDI circuits util-
ize the DMA technique in their internal
operation , there is no particular neces-
sity that the host computer have any
special talent for this sort of thing.
2. You are correct — the only disadvan-
tage is that of speed. A major advantage
of not purchasing the two-port memory
is that you will save a lot of money.
3. No — the two-port memory is the pic-
ture memory and, if filled, frees the
normal computer memory for program
and/or data retention.
4. Here, I believe, is the crux of your mis-
understanding. The picture (as retained
in the picture memory) is placed there
by a program running in the CPU. Pro-
gram memory is, of course, needed for
any such program to run. The picture
memory sets its picture via the S- 1 00
bus, and transmits it to the monitor via
the SDI two -card set.
5. The memory mapping scheme is a pop-
ular method for fitting more than 64K
of memory to a CPU which would other-
wise be limited by its 16-bit addressing
bus to that amount only. Each memory
card fitted with the bank select feature
can be turned on and off by signals
from the CPU. Since more than one
memory card can be addressed at the
same location within the 64K address
space, the CPU is careful to only turn
one of them on at any given instant. IPs
a handy (but, again, expensive) way to
keep a picture on ice and yet instantly
available for display on the monitor.
Memory mapping/bank select has wide
usage in multi-terminal microcomputer
systems.
Tom Fox
DP: QUESTIONS & ANSWERS
I am writing for information on micro-
computer controls such as those featured in
the microwave oven, electronic toys, digital
controlled television sets, and other appli-
ances. I have several inventions and would
like to incorporate the digitial control tech-
nique into them.
I have no knowledge of electronics, but
some knowledge of programming and sys-
tem operations. I can’t find a school or insti-
tution that teaches digital controls using the
microcomputer. I would appreciate any in-
formation on the teaching or building of
single chip microcomputers used specific-
ally for digital controls.
Don D. Wilson
9055 S. Luella
Chicago, IL 6061 7
Do you know of any software and/or
hardware designed for academic and/or
admissions offices of independent schools?
Louis A. Young III
P.O. Box 657
Pebble Beach, CA 93953
I would like to know how to go about add-
ing modules to expand my Exxon Qyk Level
3 word processor to a full computer. Which
products would be compatible with it?
Do you know of any articles on expand-
ing word processors into full computers?
C. A. Bodor
2699 Youngslown Rd.
Warren, OH 44484
I own an Apple II computer and I am
looking for programs on I Ching, astrology,
numerology, and biorhythms. I also need
information on computer portraiture meth-
ods, hardware and software.
Thomas A. Waye
2525 NW 105 Lane
Sunrise, FL 33322
We have published full addresses to
these letters so that our readers may offer
assistance. For books on these subjects
write Data Dynamics Technology, P. O. Box
1217, Cerritos, CA 90701, for their catalog.
WHERE CREDIT IS DUE
All the photos in the article Micro Mix-
down — There’s a 65K Helper in the Record-
ing Studio (INTERFACE AGE, January
1 980) are of the AUTOMATT in San Fran-
cisco, which was not stated in the article.
Photo 1 is Studio C, where a Harrison
40-in/32-out console is interfaced with an
Allison 65K Programmer. The Allison is in
turn interfaced with a Zilog Z-80 microcom-
puter, which is used to display the status of
the various (Harrison) console functions
and/or the corresponding data for those
functions on the multi-track recording tape.
In addition, data and text (artist’s names,
channel assignments, etc.) related to a par-
ticular song or “cut” may be displayed in-
stantly on the console.
Studio A and B also feature automation,
and Chief Engineer Michael Lamer is the
man who put it all together.
Steve L. Martin
Santa Cruz, CA
DEFINING ‘INTELLIGENCE’
In Roger Garrett’s April article, “A
Discussion of Artificial Intelligence — A
Definitive Answer to the Question: Can
Computers Think?”, his approach is in-
teresting. The scope is the whole of human
knowledge and experience. I would like to
offer the following observations to extend
Mr. Garrett’s definition.
Consider a system with internal and exter-
nal compartments and a transducer at the in-
terface of the two regions. Output from the
JUNE 1980
"Our inventory is our existence*
Think we’d trust it to anything less
than Scotch Brand Diskettes?”
Don Stone, President,
Mass. Auto Supply Company,
Inc., Boston, Mass.
Scotch Diskettes are the
diskettes you can depend upon
with the information your
business depends upon.
Each one is tested and
certified error-free before it
leaves our factory. Because we
know nothing less than
perfection is acceptable for
your vital business data.
Scotch Diskettes are
available in regular or mini
sizes, compatible with almost
any system.
To find out where you
can purchase Scotch Diskettes,
call toll free: 800-328-1300.
(In Minnesota, call collect: 612-
736-9625.) Ask for the Data
Recording Products Division. In
Canada, write 3M Canada Inc. ,
London, Ontario, N6A 4T1.
If it’s worth remembering,
it’s worth Scotch
Data Recording Products.
JUNE 1980
CIRCLE INQUIRY NO. 42
INTERFACE ACE 13
“After working all day with the computer at
work, it's a kick to get down to Basic at home. And
one thing that makes it more fun is my Shugart
minifloppy™- We use Shugart drives at work, so
when I bought my own system I made sure it had a
minifloppy drive.
“Why? Shugart invented the minifloppy. The
guys who designed our system at work tell me that
Shugart is the leader in floppy design and has
more drives in use than any other manufacturer. If
Shugart drives are reliable enough for hard-working
business computers, they've got to be a good
value for my home system.
“When I'm working on my programs late at
night, I can't wait for cassette storage. My
minifloppy gives me fast random access and data
transfer. The little minidiskettes™ store plenty of
data and file easily too.
“I made the right decision when I bought a
system with the minifloppy. When you lay out your
own hard-earned cash, you want reliability and
performance. Do what I did. Get a system with the
minifloppy."
If it isn't Shugart,
it isn't minifloppy.
wT Shugart
435 Oakmead Parkway, Sunnyvale, California 94086
See opposite page for list of manufacturers featuring Shugarf s minifloppy in their systems.
TM minifloppy is a registered trademark of Shugart Associates
LETTERS
transducer is received by a network com-
posed of various levels of functional units
that receive input from the transducer or
other levels in the network with a final out-
put pattern resulting. In a simple represen-
tation, this could be a photocell to turn on
the porch lights at dusk, or a human finger’s
temperature receptor responding to hot
water and a verbal expression of “ouch.”
If we consider the ultimate in information
about an external event to be the informa-
tion obtainable from the quanta of energy
given off, we immediately are confronted
with the limitations of information gathering.
Entropy, Heisenberg’s uncertainty principle,
the physical nature of the transducer, and
various other factors place a limit on how
much is directly knowable about any event.
Thus, the transducer can be considered to
carry out a kind of mapping function. A one-
to-one mapping function associates every
element in one group with a single element
in a second group. In the case of a
transducer, we would need an efficiency
conversion of 100%.
There is a loss of information, so the
transducer is of a many-to-one class in its ac-
tion as a mapping function. That is, some of
the information input in the form of energy
quanta are indistinguishable and would be
mapped onto the same output signal.
The levels of the human nervous system
can also be considered to carry out mapping
functions. They, too, are of a many-to-one
type. Thus, there is a loss of information
regarding an external event before we begin
processing at the level of human thought.
I would like to simply state that human
language is not always a one-to-one map-
ping, either in its ‘internal’ use or when used
to communicate information to others.
Thus, the idea of restricting a hypothetical
thinking machine to human language pro-
cessing seems a severe handicap for the ma-
chine. Trying to define a new, more precise
language or to develop a programming lan-
guage to solve this problem is approaching
the problem in reverse. An intelligent ma-
chine should get information from the source.
My use of the concept of mapping is simi-
lar to Mr. Garrett’s definition of thinking.
Equating thinking to mappings of informa-
tion to another pattern allows some things to
be defined as thinking which are not usually
considered as such. There is a wide separa-
tion, quantitatively if not qualitatively, be-
tween simple machines and humans. There
is another qualitative aspect to the definition
of thinking which creates a new category,
that is the ability to generate and implement
a new mapping function (in whatever form
— ‘hardware’ or ‘software’).
I commend Mr. Garrett on his informative
and stimulating article, and on his positive
approach to the subject.
Darwin Kenepp, M.D.
Penn-Wynne, PA
Your observation of the tendency to
equate language processing with intelli-
gence is well founded. Early attempts in-
volved simple syntactic analysis , the deriva-
JUNE 1980
tion of denotation from text. Semantic
analysis , the derivation of connotation , was
also required in order to determine mean-
ing rather than simple structure. When this
failed, other methods were employed. One
method describes “ scripts , ” or simple en-
vironments, within which the analysis takes
place. This restricts the computer's world
view, so that it knows what to expect from
the text.
The problem with all of these methods
is that they are approaching the concept of
intelligence from too high a level. Simu-
lating the expressions of intelligence is not
the same as simulating intelligence itself. It
is the phenomenon of intelligence, or think-
ing, which I was attempting to define in my
article and which you have described utiliz-
ing a slightly different approach.
You have identified perhaps the greatest
obstacle in the acceptance of this approach
when you observe that this view “allows
some things to be defined as thinking
which are not usually considered as such. ”
The obstacle stems from the distaste most
people have for a mechanistic/determinis-
tic view of the world and the presumed
“special place ” that man has in some
ethereal “scheme of things. ”
The assumptions used here are (1)
human beings are special, and (2) the abil-
ity to think, to emote, to create original
ideas is that which makes us special. The
conclusion is: non-human entities cannot
possibly think, because it would contradict
the assumptions.
In approaching the issue from a scientific
perspective, however, we can logically
make no such assumptions. We attempt to
define consistencies, to observe what ex-
ists, to measure and count, and to draw
logical conclusions regardless of precon-
ceived notions.
Our conclusions are often expressed as
models of reality, hopefully a model which
comes close to that reality. Your mapping
model and my own data/attribute/relation-
ship model are two approaches. Perhaps
one of these is close to reality; we cannot
tell how close. The results may very well
allow some things to be defined as thinking
which are not normally considered to be
thinking. But, when we are truly aiming to
reveal the truth, not merely attempting to
substantiate preconceived notions, we are
willing to accept the consequences of that
understanding.
I see your model as a description of mine
at a much higher level of conceptualization.
Language processing models (an extremely
high level of thinking) have not worked very
well. My model, purposely defined to be the
lowest possible level of conceptualization,
may prove to be difficult to implement with
current technology. Your model is
somewhere in between these extremes, and
may prove to be more easily implemented
to include expressions of intelligence such
as emotion, creativity, self-consciousness
and the desire to search for truth.
Altos Computer Systems
2360 Bering Drive
San Jose. CA 95131
Apple Computer
10260 Bandley Drive
Cupertino. CA 95014
Commodore Business Machines, Inc.
3330 Scott Boulevard
Santa Clara. CA 95051
Digital Microsystems Inc.
4448 Piedmont Avenue
Oakland, CA 94611
Industrial Micro Systems
628 N. Eckhoff
Orange, CA 92668
Micromation Inc.
1620 Montgomery Street
San Francisco, CA 941 1 1
Morrow Designs Inc.
Thinker Toys
5221 Central Avenue
Richmond, CA 94804
North Star Computers Inc.
1440 Fourth Street
Berkeley, CA 94710
Polymorphic Systems
460 Ward Drive
Santa Barbara, CA 93111
Tano Corporation
4301 Poche Court West
New Orleans, LA 70129
Technico Inc.
9051 Red Branch Road
Columbia, MD 21045
Texas Electronic Instruments
5075 S. Loop East
Houston, TX 77033
Vista Computer Company
1401 E. Borchard
Santa Ana, CA 92705
Roger Garrett
o^Shugart
VECECR mz
The presidents of the companies
making these computers recommend
Structured Systems Business Software
for one very simple reason:
Structured Systems
5204 Claremont Oakland, California 94618 (415) 547-1567
CIRCLE INQUIRY NO. 60
*SSG business software runs on these and many other microcomputer systems.
See your computer dealer for compatible hardware, or send for our brochure,
Choosing A Computer For Your Business: SSG Software and Compatible Hardware.
Structured Systems Business Software works for
business. It works as delivered, without customization
or reprogramming. It works without extensive
retraining, or any new data processing personnel.
And it works hard. Our business software turns
a computer into an efficient, hardworking employee,
to help your business work better.
We’ve got working solutions for your General
Ledger, Payroll, Accounts Receivable, Accounts
Payable, Inventory, letter writing and correspon-
dence, mailing lists, data storage and report writing.
Ready to run on any CP/M microcomputer system?
Ready to go to work for your business right now.
We help business work better, faster, and smarter.
Our Product Line Includes:
General Ledger
Accounts Payable
Inventory Control
Letteright
Accounts Receivable
Payroll
Analyst Data Storage/Report Writing
NAD Mailing System
QSORT Sort/ Merge System
CP/M is a registered trademark of Digital Research.
By Lyle Ronalds
SSI Far East Ltd.
Suite 201, Austin Centre, 21, Austin Avenue, Kowloon
This month's column will be taken from the February 1980
issue of “ Readout f ” a newsletter published by Lyle Ronalds in
Hong Kong.
The views and opinions stated in this column are those of the
author and not necessarily those of the magazine and its staff.
BUSINESS MORALITY IN HONG KONG
Here’s a story to touch your hearts; a giant U.S. electronic com-
pany undertakes to ship a sizeable consignment of components to a
small Hong Kong end product manufacturer. The U.S. company
accepts the order, and the letter of credit is opened.
Then, for reasons best known to himself, but shall we say because
of a better price from a local U.S. customer, the U.S. component
manufacturer decides not to deliver the goods, or to deliver only part
to Hong Kong, or to deliver late. The U.S. component manufacturer
thinks no more about it and goes to lunch.
In Hong Kong, the owner of the small factory does not go out to
lunch, in fact, he has not had time to go out for lunch for some
months. He has accepted an order from his own customer, and con-
tracted to deliver at a set time at a set price. He has ordered all the
other components necessary, and he has staffed up to meet produc-
tion schedules. Then, he hears that his one major component con-
signment is not going to arrive, because his U.S. supplier has sold it
to someone else. He has to renege on his promise to his customer,
and loses a great deal of money and reputation in doing so. He has
to resell at a loss all the other components he bought; and he prob-
ably also has to let a few people go who will have to find new jobs.
End of parable. Sound familiar?
Now, we’ll stick our editorial neck out: The standard of business
morality is higher in Hong Kong than it is in the U.S. While
American public companies make a great show of being socially
and morally responsible for their obligations to their employees,
customers, communities, and suppliers, it seems to us, dealing with
both Hong Kong and U.S. businessmen, that the Hong Kong
executives are the ones who are practicing what the Americans are
only preaching.
A Hong Kong businessman’s word is his contract; lawyers get fat
on digging for loopholes so that Americans can break theirs. A
Chinese company will pay upon delivery of the goods, while in the
States you’re lucky if you get your money in sixty days.
The East, indeed, has a thing or two to teach the West about
moral business conduct.D
The
Working
Analyst*
If you would like to put
a computer to work
collecting, organizing,
and summarizing
the information
you need to make
better decisions, take
a look at Analyst.
Analyst is a software
package designed to let
you store and analyze
virtually any information
involving numbers, dollars,
dates, and descriptions. Simply
tell Analyst what kind of informa-
tion you want to store. Analyst creates a com-
puterized file for that information. And Analyst
creates an information entry program for your
file that asks you for each entry, and checks your
data for errors. (You can create any number of
different files.)
Then tell Analyst what reports you want from
your data file. There are all sorts of record
selection and report formatting options, so you
can design an unlimited variety of reports to
focus on different aspects of the same data file.
Analyst is so flexible, you’ll find a million
ways to use it. It is easy to use, so you don’t need
to be a programmer to make
your computer really
work for you. If this bit
of information
intrigues you, find out
the rest. You’ll like
what you see.
Structured Systems Croup
INC«.HU*ORAUI>
Analyst is a part of a full line of working software solutions from
Structured Systems Group, all ready to run on any CP/M* microcomputer
system. For more information, see your computer retailer, or call us.
*CP/M is a trademark of Digital Research.
Structured Systems
5204 Claremont Oakland, Ca. 94618 (415)547-1567
JUNE 1980
CIRCLE INQUIRY NO. 61
This Weekend:
STIK
IT....
••to your
That's right! Esmark’s VIDIET-STIK light pen has
the TRS-80 CONNECTION for LEVEL I & II. Your
4K to 48K TRS-80 System will come alive under
your VIDIET-STIK within minutes of its arrival.
That’s because there are no wires to solder or
traces to cut. You’re up and running as fast as
you can plug the interface into your system's
cassette EAR-jack, CLOAD our custom LIGHT-
WAVE demonstration software and RUN. And
because the interface has a plug for your re-
corder. you won't have to unplug it again when
loading your other software tapes. The inter-
face allows them to pass right thru whenever
you’re not using the pen. It’s exclusive ‘switched
tip" design means the pen’s electrically iso-
lated from your system when it’s not in use.
Just point & press! It's that simple.. Plug.
CLOAD and RUN. And have we got the software
for you to RUN with! Our demonstration tape
includes a calibration program (used to adjust
the CRT’s brightness and contrast) plus STIK-
TAC-TOE. AWARI and TOWERS. Two challeng-
ing games and a puzzle that will keep grown-
ups and children Stik'ing it to your TRS-80 for
hours. And there are instructions provided so
you can begin writing your own light pen pro-
grams (lightware) for fun or profit (Level II). Or,
just sit back and enjoy our LIGHT WAVE tapes
each month. Esmark's unmatched commit-
ment to lightware can bring you up to five new
games, puzzles, drills & educational quizzes
or simulations each month. Our current LIGHT-
WAVE releases are:
LIGHT-PAK 2- LIGHTPEG (4 peg-jump puzzles)
ENDRUN (Othello with a twist )
(LEVEL II) LIFE9 (Conway’s LIFE with
mutations)
Price. $19.95 (including postage
& handling)
LIGHT-PAK 3- LITEGAMMON (Backgammon
you’ll Stik with)
(LEVEL II) STIKWUMPUS (Caves with a
little ‘life’)
MAZEMASTER (Maze after
maze to poke thru)
Price: $l9.95(including postage
& handling)
T
R
S
i
8
O
Order yours now and we ll include a free copy
of FLASHBACK, Esmark's newsletter dedicat-
ed to the latest news in lightware applications.
And don’t forget to tell your friends. The
VIDIET-STIK can also be ordered for use on
most other micro systems using the following
processor chips:
8080 Z80 6800 6502
All that’s required is a standard cassette jack
leading to Ground and a readable single bit in-
put port. Driver software is provided along with
instructions for writing lightware applica-
tions. And tell your local Dealer that Esmark’s
got a Dealer package he won’t want to miss
out on. Delivery is 3 to 6 weeks from receipt of
your order. C.O.D.'s are $3.00 extra but will be
shipped within 2 weeks. All prices are F.O.B.
Mishawaka, Indiana. Indiana residents add
4% sales tax.
ALSO COMING FROM ESMARK:
•TRS-80 Printer Interface (Cassette AUX-jack
interface for all RS232 prints. Includes LLIST
& LPRINT software)
• TRS-80 RS232 Communications Interface
(Makes your TRS-80 a full I/O terminal to time-
sharing systems the world over. Gives you
intelligent or dumb terminal capabilities at
1 10 or 300 BAUD. Also includes Printer Inter-
face above with 20 mA current loop & TTL
level I/O options.)
— TRS-80 is a trademark of Tandy Corporation—
m
2
>
X
£6
»*
•j
V)
n
ESMARK INCORPORATED
507V 2 E McKINLEY HWY. MISHAWAKA, IN 46544
(219) 255-3035 jjjgg 95
•ELECTRONIC SYSTEMS MARKETING
PLUS $1.50
POSTAGE &
HANDLING
UPDATE
TACTILE TELEPHONE POSSIBLE
Advances in robotics, coupled with recent
technologies in developing artificial limbs,
may lead to a new communication device,
according to industry analysts. A phone
equipped with a hand capable of transmit-
ting human gestures, such as pointing, feel-
ing and waving, is reportedly within the tele-
phone state-of-the-art.
Dubbed Feel-a-Phone, the system could
revolutionize conventional telecommunica-
tions by inserting expressive hand gestures
into daily telephone conversations. Words
alone lack the human emotion of a face-
to-face meeting. Gestures transmit feel-
ings and undertones that are not conveyed
by voice, but could be transmitted through
a Feel-a-Phone. An irate bill collector,
for example, could convey his anger by
violently shaking his forefinger at a late
paying customer. A business deal conducted
over the telephone could be topped off with
a hearty handshake instead of “it’s great do-
ing business with you.”
Recent developments in sensor and trans-
ducer technology, allowing for the produc-
tion of durable, precise robot “hands,” has
reportedly caused many manufacturers of
industrial robots to have backlogs stretching
well into 1981. Manufacturing plants are
turning to robots to perform a number of
tasks including machining, welding, paint-
ing, and other dirty or undesirable jobs once
performed by humans.
Some of the work corresponds to devel-
opments by the manufacturers of artificial
limbs, who produce hands that look and act
like the real thing. Research in the nuclear
industry, where manipulator hands for
weapons and power plants are widespread,
relate to Feel-a-Phone where an operator
holds material and operates machines by
remote control, using robot manipulators
guided by the operator’s finger movement
on control rings.
These techniques could be adapted in the
design of a Feel-a-Phone, but would now be
expensive. A Feel-a-Phone equipped with
multiplexers to allow for transmission of
about 60 different channels of position,
would probably cost around $5,000. An ad-
ditional voice channel would most likely be
required, bringing the cost up to $10,000.
JOB FAIRS PROMOTE
DP EMPLOYMENT
Newspaper headlines may trumpet the
dangers of recession, but human resource
directors of many national corporations
don’t believe a word of it. Personnel
specialists for advanced technology com-
panies almost unanimously repeat what to-
day is a truism in employment recruitment:
that engineers and technicians with the pro-
per credentials are riding the crest of a
“buyer’s market.”
So it is not surprising that an enterprising
Minneapolis-based company, Business
People Inc., has successfully put together a
unique job mart, appropriately called Career
Job Fair.
The promoters believe it is the first time a
non-employment agency has put so many
companies, engineers and other technical
personnel together under one roof for
match-making purposes. For companies, it
is an opportunity to conveniently and inex-
pensively meet hundreds of qualified ap-
plicants; job shoppers in turn can select
from a wide range of choices, and then
quickly — and often anonymously — visit
the desired companies.
The Career Job Fair was initiated in Min-
neapolis three years ago and more recently
has been expanded into San Jose, California
and Boston. Human resource directors are
attracted to this type of recruiting program
for a variety of reasons. Job Fair is a new
and interesting approach to more traditional
head hunting, according to Mike Dooley,
personnel manager, Cardiac Pacemakers,
Minneapolis. “It’s the optimum way for
applicants to look over a large number of
companies in one day, and for companies to
quickly meet a variety of prospects.”
Charles Patterson, professional recruiter,
Emerson Electric, St. Louis, uses the Job
Fair both because the company has “many
employment needs, and it’s a public rela-
tions opportunity to dispell a misconception
about Emerson. We are no longer in tele-
vision and radio production, and use the
Fair to acquaint the engineering market with
our high technology and engineering
work.”
The concept may be unique but the
novelty will wear out quickly without ap-
propriate recruiting results. Last spring Con-
trol Data talked to approximately 200 at the
company booth at the Minneapolis show
and employed 1 3, including 1 1 exempt
hires, according to Jim Lewis, Consultant
for Corporate Staffing. “We didn’t expect
this number of hires and we’re extremely
pleased with the results.” At the same show
Honeywell made six major hires. At the
Boston show Emerson recruited 12 and
hired six and at Los Angeles employed
seven. Signetics Corporation, Sunnyvale,
did not reveal recruitment totals at the
California show, but Dan Barryman, profes-
sional recruiter, considered his results to be
“cost effective.”
COBOL WINS GSA OK
Even though COBOL has been a stan-
dard industry language for some 20 years
and is one of the languages of choice for
government applications, it has only recent-
ly won official certification by the General
Services Administration.
Developed by Micro Focus Ltd., London,
England, and marketed in the United States
by Micro Focus Inc., Santa Clara, California,
CIS COBOL is a portable software system
for compiling, debugging and executing
COBOL programs.
18 INTERFACE AGE
CIRCLE INQUIRY NO. 28
JUNE 1980
THE ULTIMATE
INFORMATION
MANAGEMENT SYSTEM
The brain is the perfect information management
system.
Like the brain, we at Micro-Ap specialize in the
management of data.
Our software is the state of the art and is
designed to efficiently store and instantly report
the information you need for your business and
personal needs.
From inventory control to mailing list manage-
ment, Micro-Ap provides the most cost effective
software available.
At the heart of our systems are Micro-Ap's unique
indexing and reporting methods. You are not
limited to single key retrieval. Information can be
referenced by zip code, date, name, or any other
indices required. Operation is “menu driven" and
uses screen displays with all the instructions and
$rror sensing that allow the novice to quickly
learn the system and accomplish a multitude of
tasks.
Micro-Ap's Newest Industry Innovation is the
SELECTOR IV ,m System, with the ability to make
data file conversions, arithmetic computations,
global search and replace, and full page report
formatting.
This floppy and fyard disc oriented system is
upward compatible with SELECTOR III-C2 lm
It adds several dimensions to the world of infor-
mation management.
Experience - SELECTOR” 11 has been around,
and improving, longer than any other data base
system in microcomputers.
See the innovative SELECTOR IV ,m data base
manager and the standard setting GLector,
general ledger system at YOUR LOCAL
COMPUTER STORE or contact:
Micro-Ap Lifeboat Associates
9807 Davona Dr. 2248 Broadway
San Ramon, Ca. 94583 NY, NY 10024
(415) 828-6697 (212) 580-0082
telex 220501
MIGRO*AP 9
The Standard In Information Management Systems
CIRCLE INQUIRY NO. 45
uruA i c
Although it has only been available for a
short time, it has become an industry stan-
dard for microcomputer COBOL operations
with OEMs and end users. A major feature
of the package is that it can be used with the
RAM available in microcomputers (usually
up to 64K bytes).
Since most COBOL applications require
user participation as well as compactness,
CIS COBOL is also interactive. This feature
shortens program development time by
allowing the user to debug programs in in-
crements on a CRT screen. In real time
applications, the interactive feature’s run
time option module displays a full screen of
data on a CRT screen with a single COBOL
language command.
Some 100,000 lines of COBOL test
source code was successfully processed to
achieve GSA certification at this level. These
tests were devised and administered for the
GSA by the Federal Compiler Testing
Center, which administers them on request.
CIS COBOL is supplied to users with a
compiler, Run Time System and interface
module. The compiler and Run Time Sys-
tem are portable to new environments. The
Run Time System is usually written in the
assembler language of the target micro-
computer which can be an Intel 8080, or
8085, a Zilog Z80 or a DEC LSI-1 1 .
The CIS COBOL interface modules are
specific to operating systems. These sys-
NAME (Print)
ADDRESS
CITY
Please send me:
Binders @ $7.50 each
Slip Cases @ $5.95 each
Shipping & Handling Charges
$1 .50 ea. U.S.; $2.00 ea. Foreign
□ Check or Money Order (U.S. Funds drawn on U.S.
□ Visa#. □ M/C#
Exp. Date Signature
terns include CP/M for the Z80, the RT-1 1
for the LSI-1 1 and the ISIS-II for Intel’s In-
tellec development systems. The interface
module is the only CIS COBOL feature that
is not completely interchangeable.
MINICOMPUTER REVENUES TO
REACH $13 BILLION BY 1983
Throughout the 70s, the minicomputer
market experienced dynamic growth rates in
terms of both revenues and unit shipments.
International Data Corp., Waltham, Mass.,
has closely watched this market over the last
seven years. Its latest report concludes: Unit
growth to decline steadily over the next few
years, with demand from OEM customers,
in particular, dropping significantly. Despite
shrinking shipments, revenues will continue
to show healthy, although slower, growth —
increasing 29% per annum through 1983.
At that point, the minicomputer market will
be worth some $13 billion (with expectations
for unit shipments reaching 235,000 units).
Some manufacturers (DEC for example)
have taken steps to prepare for the expected
downturn by cutting back on production
and the building of new plant facilities. The
strong revenue projections forecasted are
due primarily to an expected increase in em-
phasis on service, software and add-on
peripherals. In many cases, minicomputer
manufacturers are enhancing their
peripheral equipment operations to the
point where many are actively marketing
these products on an independent basis.
One major finding of IDC’s research was
significant increases in overseas revenues by
a number of U.S. suppliers. Reasons in-
clude a generally higher average value per
system for overseas shipments, and also in-
ternational users taking advantage of the
declining dollar in relation to their own cur-
rencies. By 1 983, 39% of all revenues for
U.S. manufacturers will be derived from
overseas business with international
shipments reaching 32% of the total.
SOUTHERN SYSTEMS NAMES
U.K., FRANCE REP
The London-based firm of Peripherals,
Computers, Memories & Leasing is
representing Southern Systems Inc., Fort
Lauderdale, Fla., in the U.K. and France in
marketing SSI’s printer systems.
PCML will handle the firm’s full line of
medium and high speed impact printer sys-
tems, with special emphasis on SSI’s most
recently introduced systems, the B-300, the
B-600 and the M-200.
PCML also will market SSI’s 2200 family
of printer systems, based on 300, 600 and
900 line-per-minute drum printers; the
2550, a 1500 line-per-minute Charaband
printer; and the CT 1 200 family, 600, 1 000
and 1200 line-per-minute ChainTrain
printer systems.
GATHERING SEEKS INPUT
Midcon/80, the Southwest’s major high-
technology convention and exhibition
scheduled November 4-6 in Dallas, has
issued a Call for Sessions. Manuscript sub-
mission deadline is July 25.
Each Midcon session will include three to
five related papers covering, but not limited
to, automotive electronics, communica-
tions, computers and microprocessors, con-
sumer electronics, design automation,
digital signal processing, electromagnetic
compatibility, energy, instrumentation and
measurement, manufacturing and testing,
memories, office automation, petroleum
electronics, reliability and quality control
and semiconductor technology.
Contact Dale Literland, Educational Acti-
vities Manager, Midcon, 999 N. Sepulveda
Blvd., El Segundo, CA 90245.
MORE IN EDUCATIONAL
COURSEWARE
With an eye on the increasing use of per-
sonal computers in the home as an educa-
tional tool, Science Research Assoc, and
Atari, both of Sunnyvale, CA, have com-
bined their expertise in developing a multi-
faceted educational computer courseware
package for use in the classroom and at
home.
Science Research will develop software in
such program areas as reading, languages,
math, science and social studies, and Atari
will market them in public and private
schools from preschool through to the
university level.
' LET US SLIP ONE
OVER ON YOU. .
INTERFACE AGE
Binders and Slip
Cases protect a full
year — 1 2 issues —
from dust; damage; and
keep your magazines in
one place, at your fingertips,
whenever you need them. Each
Binder and Slip Case is constructed
of a handsome blue vinyl with
INTERFACE AGE stamped in gold foil
on the front cover and spine.
DATA DYNAMICS TECHNOLOGY
P.O. Box 1234, Cerritos, CA 90701
_ STATE_
TOTAL ORDER $_
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•California residents add 6% sales tax. Availability and prices quoted subject to change without notice. Please allow 6 weeks for
delivery You may photocopy this page to keep your INTERFACE ACE intact. Orders cannot be shipped unless accom-
panied by payment, including shipping & handling and tax where applicable.
DATA DYNAMICS TECHNOLOGY. A Division of INTERFACE AGE Magazine (213) 926-9544
20 INTERFACE AGE
JUNE 1980
THANKS FOR
THE MEMORIES
Thanks to these inexpensive Pet and TRS-80 memories and disk drives you can instantly
increase your personal computer’s capacity, capability and versatility.
Expend your Pet.
Disk Drives: Choose either double density 400k or dual head
double density 800k on-line disk drive. Both with DOS operating
system including 17 additional BASIC commands and random
or indexed sequential access.
Exceptionally fast 5,000 bytes per second (including verify)
transfer speed lets you load 20k program in just 3 seconds.
Model 8k must have Expandamem™ to operate disk drives.
All other models are plug compatible.
400k only $1295. 800k only $1695.
Expandamem™: Lets you expand the size and scope of your
programs. 16k 24k, and 32k internal memory boards give you 8k
of assembly language subroutines accessed via the USR command.
16k only $425. 24k only $525. 32k only $615.
Software: Complete library available. Write for details.
Expand your TRS-80.
Disk Drive: Single density dual head 400k on-line disk drive is
completely compatible with TRS-80 DOS and uses own controller.
Only $1295. I
IMMEDIATE DELIVERY! ORDER TODAY!
COMPU ‘INK
965 W Maude, Sunnyvale. CA 94086
(408) 245-4033
Please send me the following:
□ Pet Disk Drive □ 400k □ 800k
□ Pet Expandamem™ □ 16k □ 24k □ 32k
□ Pet Software (Info only)
□ TRS-80 400k Disk Drive
□ Name of my nearest Computhink dealer
Total enclosed: $
Check or Money Order only. Calif. Res. add 6% tax.
Freight pre paid in continental U S.
Dealer Inquiries Invited.
CIRCLE INQUIRY NO. 14
■ /ii rm in an
LflLCI ULJ^n
SMALL COMPUTERS AND THE
PROFESSIONAL
The Computers and Communications
Committee of the Engineering Society of
Detroit (ESD) will conduct a seminar on
June 4 entitled “Small Computers and the
Professional.” The program is designed to
meet the information needs of business pro-
fessionals who are considering a purchase
or expansion of a small computer system.
For more information contact Carol Lynn,
100 Farnsworth, Detroit, Ml 48202, (313)
832-5400.
COMPUTER CAMP
In Moodus, Connecticut, June 29-July 4,
youngsters can sign up for a week long
camp where the main activity will be com-
puters.
Kids from ages 10-17 will enjoy small
group instruction and mini and microcom-
puters for ample “hands-on” experience.
The camp is for kids of all levels of ex-
perience including no experience what-
soever. For more information contact
Michael Zabinski, Computer Camp, Grand
View Lodge, Box 22, Moodus, CT 06469,
(203) 795-9069.
SOFTWARE PLANNING SEMINAR
Polytechnic Institute of New York and the
Institute for Advanced Professional Studies
are presenting a three-day seminar for
design, test, and diagnostic engineers and
managers.
The seminar, entitled “Diagnostic Soft-
ware: Planning and Design” will include
design examples, lectures, informal sessions
with instructors, as well as individual and
group diagnostic programming sessions.
The seminar will be held July 1 4- 1 6 at the
Sheraton-Lexington Motor Inn, Lexington,
Massachusetts. For details contact the In-
stitute for Advanced Professional Studies,
One Gateway Center, Newton, MA 02158,
(617) 964-1412, Prof. Donald French.
SUMMER CES
The 1980 Summer Consumer Elec-
tronics Show will be held June 1 5-June 1 8
in Chicago and will utilize three exhibit
facilities — McCormick Place for all con-
sumer electronics products, McCormick Inn
for audio components demonstration rooms
and the Pick-Congress Hotel for demonstra-
tion rooms and suites for special interest
audio components.
Exhibits will include audio compact and
component systems, audio tape equipment
and software, auto sound, video tape
recorders, videodisc systems, electronic
games, home computers and more.
For more information contact Consumer
Electronics Shows, Two Illinois Center,
Suite 1607, 233 N. Michigan, Chicago, IL
60601, (312) 861-1040.
MICROCOMPUTER INTERFACING
A two-week short course on the funda-
mentals of microcomputer interfacing will
be offered by the Virginia Military Institute
from July 14 through July 25.
This will be a hands-on laboratory ori-
ented course which will feature the TRS-80
microcomputer (Level II with 16K).
For details contact Dr. Philip Peters,
Dept, of Physics, VMI, Lexington, VA
24450, (703) 463-6225.
1980 MICROCOMPUTER SHOW
The 1 980 Microcomputer Show & Inter-
national Conference will be held at the
Wembley Conference Centre, London,
England, July 22-24.
Aspects examined and on display will in-
clude industrial applications, micro based
commercial systems, micros in DP, and ad-
vanced micro system design.
Contact TMAC, 680 Beach St., Suite
428, San Francisco, CA 94109, (800)
227-3477, (in Calif, and Canada (415)
474-3000).
VIDEOSPACE 1980
Videospace 1 980 is a consumer show to
demonstrate the latest technology and
educate consumers in home video and
commercial electronic living.
The show will feature workshops, guest
speakers, computers, special exhibitions
Our MacroFloppy
goes twice the distance.
For s 695.
Introducing the Micropolis MacroFloppy™ :1041 and :1042 disk drive sub-
systems. For the S-100/8080/Z-80 bus. Packing 100% more capacity into a
5%-inch floppy disk than anyone else. 143K bytes, to be exact. For as little
as $695.
The MacroFloppy:1041 comes with the Micropolis Mod I floppy packaged
inside a protective enclosure (without power supply). And includes an S-100
controller Interconnect cable. Micropolis BASIC User's Manual. A diskette con-
taining Micropolis BASIC, and a compatible DOS with assembler and editor.
The .1041 is even designed to be used either on your desk top, or to be inte-
grated right into your S-100 chassis.
The MacroFloppy:1042 comes with everything the :1041 has, and more.
Such as d.c. regulators, its own line voltage power supply, and, to top it off,
a striking cover. Making it look right at home just about anywhere.
Both MacroFloppy systems are fully assembled, tested, burned-in, and
tested again. For zero start-up pain, and long term reliability. They're also
backed up by our famous Micropolis factory warranty.
And both systems are priced just right. $695 for the MacroFloppy: 1041
and $795 for the MacroFloppy:1042.
You really couldn't ask for anything more.
At Micropolis, we have more bytes in store for you.
For a descriptive brochure, in the U.S. call or write Micropolis
Corporation, 7959 Deering Avenue, Canoga Park, California 91304. Phone
(213) 703-1121.
Or better yet, see your local dealer.
MICROPnUS
More bytes in store for you.
22 INTERFACE AGE
JUNE 1980
and displays of video hardware, security sys-
tems, personal computers and more.
Videospace 1 980 will be held at Seattle
Center, North Court, July 25-27. For details
contact Michael Gaines, Rising Starr Pro-
ductions, P.O. Box 17209, Seattle, WA
98107, (206) 682-7724.
COMPUTER GRAPHICS WEEK
Harvard Computer Graphics Week 1 980
will be held July 28-August 1 at the Hyatt
Regency Hotel in Cambridge, Massachusetts.
There will be discussions and examples of
applications of business graphics and com-
puter mapping in the commercial, educa-
tional, and governmental sectors, including
displays of the most recent developments in
graphic hardware.
Contact Kathy Devaney, Center for Man-
agement Research, 850 Boylston St.,
Chestnut Hill, MA 02167.
SILICON CONFERENCE
The Third International Conference on
Neutron Transmutation Doping of Silicon
will take place August 27-29 in Copenhagen.
Topics for the conference include trans-
mutation physics, radiation defects, irradia-
tion techniques, material properties and spe-
cifications, device applications, new devices
and new materials.
Contact Motorola Inc., Semiconductor
Group, P.O. Box 2953, Phoenix, AZ 85062.
FIFTH BIG YEAR FOR PCC
The Fifth Annual Personal Computing
and Small Business Computer Show,
PCC’80, will be held on August 21-24 at
the Philadelphia Civic Center.
The show features exhibits and seminars
highlighting all aspects of personal and
small business computing.
For more information contact John Dilks,
Personal Computing ’80, Route 1 , Box
242, Ward Rd., Mays Landing, NJ 08330,
(609)653-1188.
NEW JERSEY COMPUTER SHOW
The 1 980 New Jersey Personal Compu-
ter Show and Fleamarket will be held Sep-
tember 27-28 at the Holiday Inn (North), at
Newark International Airport (NJ Turnpike
Exit 14).
The show will feature an indoor commer-
cial exhibit area, a large outdoor fleamarket
and user group meetings/forums on the
TRS-80, PET, Apple, Heath and other
popular systems.
For more information write NJPCS,
Kengore Corp., 9 James Ave., Kendall
Park, NJ 08824.
MINI/MICRO SHOW
The Mini/Micro Computer Conference
and Exposition will be held at Brooks Hall/
Civic Auditorium, San Francisco, California
on Oct. 14-16.
For further information contact Robert D.
Rankin, Managing Director, Mini/Micro
Conference and Exposition, 32302 Camino
Capistrano, Suite 202, San Juan Capis-
trano, CA 92675, (714) 661-3301.
PERSONAL AND BUSINESS
COMPUTER SHOW
The Midwest Personal & Business Com-
puter Show will be held at McCormack
Place in Chicago from Thursday, October
16 through Sunday, October 19. Show
hours are Thursday-Saturday: 1 1 a.m. to
9:30 p.m.; Sunday: 1 1 a.m. to 6 p.m.
For more information contact National
Computer Shows, P.O. Box 678, Brook-
line Village, MA 02147, (617) 524-0000.
PERSONAL COMPUTER FAIR
The Northwest Computer Society and the
Pacific Science Center will be holding the
third annual Personal Computer Fair Nov.
8-9. The fair will be held in Seattle, WA. at
the Pacific Science Center.
The theme of this year’s Fair is “Hands
On.” The booths and exhibits will reflect this
idea, with the public having access to as
many computers and terminals as possible.
There will be presentations for the beginner
as well as the experienced professional.
For more information contact the North-
west Computer Society, P.O. Box 4193,
Seattle, WA 98119.
MetaFloppy goes
The Micropolis MetaFloppy™ gives you more than four times the capacity of
anyone else's 5 14-inch floppy Because it uses 77 tracks instead of the usual 35.
The field-proven MetaFloppy with thousands of units delivered, comes
in a complete family of models. And, like our MacroFloppy™ family of disk
drives, MetaFloppy is designed for the S-100/8080/Z-80 bus.
For maximum capacity, choose our new MetaFloppy:1054 system. Which
actually provides you with more than a million bytes of reliable on-line stor-
age. For less money than you'd believe possible.
The MetaFloppy:1054 comes complete with four drives in dual config-
uration. A controller. Power supply. Chassis. Enclosure. All cabling. A new BASIC
software package. And a DOS with assembler and editor There's even a built-
in Autoload ROM to eliminate tiresome button pushing.
If that's more storage than you need right now, try our
MetaFloppy:1053, with 630,000 bytes on-line. Or our Meta-
Floppy:1043, with 315,000 bytes on-line. Either way, you can
expand to over a million bytes on-line in easy stages, when you
need to. Or want to.
In other words, if your application keeps growing, we've got
you covered. With MetaFloppy.
The system that goes beyond the floppy.
For a descriptive brochure, in the U S. call or write Micropolis
Corporation, 7959 Deering Avenue, Canoga Park, California 91304
Phone (213) 703-1121.
Or better yet, see your local dealer.
beyond
MICROPnLIS"
More bytes in store for you.
JUNE 1980
INTERFACE AGE 23
BOOK REVIEWS
NORTH STAR
Ace Reporter means business!
This superb data base manager
and report writer gives you posi-
tive control over every aspect of
your business.
Accurate information, promptly
available and well presented, can
save you money and increase
your profits.
Information about receivables,
payables, sales prospects, sched-
ules, inventory, cost tracking,
estimating. Information organized
the way you want it and presented
the way you need it, in tables,
labels, statements.
Ace Reporter helps you design
a data base to your personal
specification. And report formats
that tell you just what you need
to know. In a few minutes at
your terminal even if you have
absolutely no programming
experience.
You can’t afford not to have
Ace Reporter working for you.
It puts you in control. It gives
you the edge for lower costs and
higher profits.
Ace Reporter starts earning
for you the day it arrives. But it
won’t arrive until you order it.
Order today for just $240 in-
cluding disk and excellent man-
ual. (CA add $14.40 tax).
RLM Associates
1077Ticonderoga
Sunnyvale, CA 94087
(408) 245-9441
ACE REPORTER
THE HOME COMPUTER
REVOLUTION
By Ted Nelson. The Distributors,
South Bend, IN. 224 pages, $2
Review by Susan Grace
Nelson’s purposes in writing this book
were to “explode” the myths surrounding
computers and to explain the basics of com-
puter knowledge. He succeeds in both areas.
In trying to explain why these myths exist,
Nelson makes the observation that people are
scared off by the mathematical sound of the
term “computer”; this goes hand-in-hand
with the more widely-held belief that not just
anyone is capable of using a computer.
The fact that I have a limited knowledge of
computers, yet could understand most of
the ideas being explained attests that Nelson
succeeds in his purpose of instructing the
reader in the basics of computer knowledge.
However, there are some areas that need
more clarification for the beginner. The most
difficult area, in terms of comprehension, is
the section on computer languages, entitled
“Tough, Optional Part.” Another chapter
that was slower-going concerned program-
ming. A glossary of terms would have been
helpful, not only here but in other parts of the
book as well. It was difficult to go back and
find the meaning of an unfamiliar term that
popped up in the text, but this is partly due
to the organizational structure of the book.
For the most part, The Home Computer
Revolution is readable, because the book is
written in a conversational style. Nelson’s en-
thusiasm for his subject is obvious, and he
exemplifies a point he makes early in his book:
“The computer is a machine that brings out
the kid in all of us.” However, his style and
enthusiasm can almost be described as juve-
nile at times. Example: “Surprise! There are
thousands of different computer languages.”
On an introductory level, this book is a
good starting point for anyone interested in
the who, what, when, where, why and how
of computers.
After all, “a computer is simply a blank
device whose purpose is chosen and whose
steps are chosen by a human being,” Nel-
son says. He also emphasizes that the true
use of computers is for personal use.
Hey, did anyone just hear a myth ex-
plode?D
DESIGN OF TRANSISTOR
CIRCUITS, WITH
EXPERIMENTS
By Dr. Keats A. Pullen, Jr.
Group Technology, Ltd.,
Check, VA. 508 pages, $12.95
Review by Michael Scott
Providing the background and explana-
tions necessary to teach the reader the art of
designing transistor circuits, this book is par-
ticularly useful in helping experimenters,
amateurs, scientists, and engineers whose
principal areas of activity are in fields other
than electronics to develop an understand-
ing of electronic circuits. Simple, valid ex-
planations of the way solid state devices
work and how they should be used are backed
up with experiments that can be performed
to verify the correctness of the statements.
The sound basic understanding developed
will make the study of other books on elec-
tronics easier including those on microcom-
puters. Concepts rarely encountered in stan-
dard textbooks are shown to be important in
the practical application of active devices.
Topics covered include basic theory, dif-
ferences between linear resistances and the
non-linear resistances on which solid-state
devices are based, the relationships and
applications of npn and pnp transistors, field
effect devices, special purpose devices, eval-
uation of measurement devices, and special
measurement problems.
Six appendices provide information about
the Ebers-Moll model for an active device,
useful circuits, instruments, and com-
ponents; suggested supply sources for parts;
additional experiments; and the character-
ization of active devices. □
OPERATING SYSTEMS -
CONCEPTS AND PRINCIPLES
By John Zarrella. Microcomputer
Applications. 140 pages, $6.95
Review by Alfred A. Adler, Ph.D.
In this first book of a series, Zarrella notes
in the preface that books on computer soft-
ware and hardware are “written on two
levels — one for the computer science
graduate student and one for the program-
mer attempting to learn a language on a
specific computer.” He feels that a need ex-
ists for a more intermediate level. He states,
“This series is therefore dedicated to ex-
plaining some fundamental software engi-
neering concepts, techniques and terms,
and giving you, the reader, a feeling for the
scope of the design problem.”
In any technical field, the terminology is
the first and quite possibly the biggest hurdle
that must be overcome by the beginner. The
computer field is probably the worst offender
in this regard. Zarrella makes a valiant effort
to cover as many buzz words as possible,
putting them in boldface type as they arise in
the text and devoting one-quarter of the
book to a rather comprehensive glossary.
The book attempts to cover the entire
broad range of operating systems, including
multiprogramming, real time operations,
multiuser, multiprocessing, system services,
system support, scheduling, resource and
memory management, input and output, file
systems, and system security. The result, in
only 1 00 pages, is a superficial description
of what the words mean, and possibly who
might want it and why. It certainly provides a
wide angle view of the subject and gives the
reader some feeling for the breadth of the
problem, but at the same time leaves him
with an empty feeling that he has really not
learned much. The glossary covers 34
pages with some 230 entries.
The book should prove useful to anyone de-
siring a broad brush, quickly read treatment
of the field of operating systems, without
getting involved in anything heavy.D
24 INTERFACE AGE
CIRCLE INQUIRY NO. 54
JUNE 1980
Set fire
to your
paperwork.
Dispatch your paperwork with burning speed.
With Spell Binder and a microcomputer you can
set fire to just about any paperwork task in your
office. Spell Binder is a software system that will
drastically reduce the time you spend on paper-
work, and increase your output.
WORD PROCESSING. Spell Binder is a word
processing system you can learn to use in twenty
minutes. But ease of use does not mean lack of
powerful features. Compare Spell Binder’s
capabilities with any other word processing sys-
tem. You’ll be impressed. And Spell Binder
doesn’t stop with word processing.
MAILING LIST, MASS MAILING. Spell Binder
features full mailing list and mailing label capa-
bility. And Spell Binder will merge your letter with
your selected mailing list for personalized, tail-
ored mass mailings. Sort and select by any key
you want, including zip code.
CUSTOM PROGRAMMING. Using Spell
Binder’s Macro Programming feature, you can
shape your text to virtually any format, number
the lines on legal text, create custom heads for
running pagination, or do whatever you need for
a fired up paperwork flow.
HOT, NEW, NOW. This new package is the
best paperwork system you’ll find on a micro-
computer. It runs on computers with CP/M®,
including the new Heath WH89. Spell Binder is
available now. If it is not in your computer
dealer’s store for a demo, call us right away.
Before your paperwork load turns into a real fire
hazard.
CP/M is a registered trademark of Digital Research.
Spell Binder is a trademark of Testan Scientific Instruments.
r guornk mcnc
— GOIvPWER-GG — *
2601 Blackburn. Davis, California 95616. (916) 756 2921
*A lot
JUNE 1980
CIRCLE INQUIRY NO. 7
INTERFACE AGE 25
COMPUTER CLUB DIRECTORY —
As a service to our readers, INTERFACE AGE is initiating a club directory to inform readers of clubs in their areas. To add your club to this
directory, send club name, address and phone contact information to Club Editor, INTERFACE AGE, P.O. Box 1234, Cerritos, CA 90701 .
AMATEUR COMPUTER GROUP OF
NEW JERSEY
1 776 Raritan Rd., Scotch Plains, NJ 07076
Jeff Kashinsky, President
(201) 536-1078
AMATEUR RADIO RESEARCH AND
DEVELOPMENT CORPORATION
1 524 Springvale Ave., McLean, VA 22101
Paul Rinaldo, President
(703) 356-8918
BOSTON COMPUTER SOCIETY
17 Chestnut, Street, Boston, MA 02108
(617) 227-9178
NEW ENGLAND COMPUTER SOCIETY
P.O. Box 198, Bedford, MA 01730
Eric Johannson
(617) 562-6716
PHILADELPHIA AREA
COMPUTER SOCIETY
P.O. Box 1954, Philadelphia, PA 19105
PACS Hotline
(215) 467-0177
ROCHESTER AREA
MICROCOMPUTER SOCIETY
P.O. Box 90808, Rochester, NY 14607
Mike Ciaraldi
(716) 467-0177
ALAMO COMPUTER ENTHUSIASTS
4847 Castle Shield, San Antonio, TX 78218
David Samson
(512) 656-8469
COMPUTER HOBBYISTS GROUP
OF NORTH TEXAS
P.O. Box 1344, Grand Prairie, TX 75051
Garrett Davis
(214) 559-2710
CRESCENT CITY COMPUTER CLUB
University of New Orleans
P.O. Box 1097
New Orleans, LA 70122
David Hughes
(504) 271-5540
DENVER AMATEUR COMPUTER
SOCIETY
1 380 S. Santa Fe, Denver, CO 80223
Mike Dmytrasz
(303) 697-5800
SOUTHEASTERN MICHIGAN
COMPUTER ORGANIZATION
Box 02426, Detroit, Ml 48202
S.E.M.C.O. Newsline
(313) 775-5320
UTAH COMPUTER ASSOCIATION
378 East 9800 South, Sandy, UT 84070
Lawrence Barney, President
(801) 571-9661
SPACE COAST MICRO
COMPUTER CLUB
c/o Ray Lockwood
315 Inlet Avenue, Merritt Island, FL 32952
Ray Lockwood, President
(305) 452-2159
HOMEBREW COMPUTER CLUB
P.O. Box 626, Mountain View, CA 94042
Bob Reiling, President
(415) 967-6754
NORTHWEST COMPUTER SOCIETY
P.O. Box 4193, Seattle, WA 98104
(206) 284-6109
SAN DIEGO COMPUTER SOCIETY
P.O. Box 85137, San Diego, CA 92138
(714) 571-5550
SOLUS COMPUTER CLUB
1690 Woodside Road, #219
Redwood City, CA 94061
S. Sokolow
(415) 368-3331
CONNECTICUT COMPUTER CLUB
c/o Leo Taylor
1 8 Ridge Court W., West Haven, CT 06516
Leo Taylor
(203) 933-5918
TCUG (TRS Computer User’s Group)
P.O. Box 2235, Reston, VA 22090
Ron Hickey
(703) 241-2878
PROTEUS (International Processor
Technology User’s Group)
1690 Woodside Road, #219
Redwood City, CA 94061
S. Sokolow
(415) 368-3331
CONTROL PROGRAM
FOR MICROCOMPUTERS
ENABLING YOU TO RUN
SOFTWARE PUBLISHED
FOR CP/M 1.4 ON THE
TRS-80 MODEL II
for the TRS-80®Model II
CP/M is considered the industry standard disk operating system because it gives you
the hardware-independent interface you need to make your computer work for you
CP/M 2.0 is the latest in the evolution of a proven reliable and efficient software
system. FMG CORPORATION'NOW OFFERS THE CP/M 2.0 FOR THE TRS-80 M00EL II. It
features an enhanced upward compatible file system and powerful new random
access capabilities. The CP/M 2.0 from FMG provides the ability to run software
published for the CP/M system, on the TRS-80 Model II. From minidisks, floppy disks,
all the way to high-capacity hard disks, the flexibility of CP/M 2.0 makes it a truly
universal operating system. The package includes an 8" system disk, editor, assembler
and debugger for the TRS-80 Model II.
CP/M is a registered trademark of Digital Research Corp. TRS-80 is a registered trademark of Radio Shack
PRICE
$ 200.00
Manual Only
$ 25.00
VERSATILITY
For Your TRS-80 Model II
'CORPORATION
5280 Trail Lake Drive
Suite 13
Ft. Worth, Texas 76133
(817) 294-2510
BUSINESS APPLICATIONS
FROM THE ORIGINATOR OF THE TRS-80 PROJECT
Call or Write
for Complete
Information
• USER ASSIGNABLE
ACCOUNT NUMBERS
HIGH SPEED ASSEMBLY
LANGUAGE PROGRAM
• 18 DIGIT ACCURACY
ING TO
EDGER
INVOICE AGING
G WITH
INVOICE DETAIL
(Requires minimum 32K, two drives and CP/M)
WMi* Mb'
* / -fmj • j • j / t l d / »
ACCOUNTS RECEIVABLE
Accounts receivable is a low volume in-
voice system. An entry may be invoiced
at any time — before ready for billing,
when ready, after billed, even after paid.
It even has progress billing which keeps
track of milestone payments made at
intervals. The program allows automatic
posting to the General Ledger and will
interface with a future mailing list pro-
gram for making bulk mailings to cus-
tomers. Accounts Receivable does not
print invoices. Reports:
Not billed
Open and Closed Invoices
Aging Analysis
Customer Statements
Customer Activity List
ACCOUNTS PAYABLE
Accounts Payable is an invoice linked
system which means that everything re-
volves around the invoice. The system
provides the user security through the
use of a password. It allows automatic
(complete or partial) payment of selected
invoices, and automatic distribution of
each invoice to as many as eleven differ-
ent general ledger accounts
This system maintains vendor activity,
automatically posts accounts payable
and cash accounts, and will interface
with a future mailing list program.
Reports Open and Closed Item Listing
Aging — 30/60/90 days (or user
selected)
Transaction printing for Audit Trail
Accounts Payable Ledger
Customization
is available at
additional
i
PRICE EACH
$250.00
26 INTERFACE AGE
CIRCLE INQUIRY NO. 30
JUNE 1980
An Entire Family of Disk Drives for
APPLE, TRS-80*, and S-100 Computers
NOW! ALL DRIVES
COMPATIBLE WITH
MODEL II
Only LOBO DRIVES offers you an entire family of
fully-compatible disk drives to select from.
Whatever computer you’re using, APPLE, TRS-80,
or S-1 00, you can add a LOBO drive now, with the
peace-of-mind of knowing there’s a whole family of
drives available when you’re ready to expand.
And every drive you order comes complete with
chassis and high reliability power supply. Each
drive is 1 00% calibrated, burned-in, and
performance tested on either an APPLE, TRS-80,
or S-1 00 computer before it’s shipped. We are so
proud of our drives . . . our quality, reliability, and
performance, that we back-up every drive with a
one year, 1 00% parts/labor warranty.
400 SERIES FLOPPY DISK DRIVES
Meet our low-cost 5.25-inch
mini drive that records data
in either hard or soft
sectored format. It is
available in single or double
density configurations, with a total storage
capacity of 220K bytes.
800/801 SERIES FLOPPY DISK DRIVES
Here is our dual 8-inch
Floppy disk memory unit. It
records and retrieves data
on standard 8-inch
diskettes to provide 800K
unformatted, or 51 2K bytes
935 Camino Del Sur
Goleta, California 93017
(805) 685-4546
“CAN YOU REALLY AFFORD
TO PAY LESS?”
bytes of data storage
INTERNATIONAL
in IBM format per drive. It is also available with
double-sided, double-density capabilities, fora
maximum storage capacity of 1 .6 Megabytes.
7000 SERIES HARD DISK DRIVES
The latest member of our
drive family, the Series
7000 is an 8-inch, 1 0 Mega-
byte Winchester Technology,
hard disk drive. It is fully
hardware/software compatible and comes
complete with disk controller. Now you can have
the convenience, speed, reliability, and all the
storage capacity you need.
Call or write for the complete LOBO DRIVES story.
Find out just how competitively priced a quality
drive can be.
Quantity discounts available -
Dealer inquiries invited.
Yes, I want to know more about LOBO Drives
and what they can do. Send me information on:
□ TRS-80 □ APPLE □ S-1 00
□ 5 1 /4-in. Floppy drive □ 8-in. Winchester hard
disk, 10 Mbyte drive
□ 8-in. Floppy drive □ Double density
Single sided expansion interface
Double sided
Name :
Company _
Address
City State Zip
Phone No.
If dealer, provide resale no.
#TRS-80 is a registered trademark of Radio Shack, a Tandy Company.
JUNE 1980
CIRCLE INQUIRY NO. 41
INTERFACE AGE 27
• Simple Design
• Simple Maintenance
• Simple Interfacing to:
- Apple
- Pet
- TRS-80
- Exidy
-OSI
and many other
personal computers
LRC
EATON
MODEL 7000+
IMPACT PRINTER
OO+ ^
The 7000+ was designed to provide the per-
sonal computer user with an inexpensive, yet
reliable printer. Take a look - you won't regret it!
SPECIFICATIONS
• Impact Unidirectional
• 1.25 LPS; 50 CPS
• 40 or 64 Column
• 5 x 7 Dot Matrix
• Standard Paper Rolls
• lOO Million Character Printhead
Life (minimum)
• 6 LPI Line Spacing
Substantial Dealer Discounts are Available.
OEM inquiries are invited. Please contact:
SIGMA INTERNATIONAL, INC.
P.O.Box 1118 SCOTTSDALE, AZ 85252 USA
Tel. (602) 994-3435 Tlx. 165-745 Sigma Cable: SIGMAS
CIRCLE INQUIRY NO. 58
TARBELL HAS HIGH-QUALITY S-100 HARDWARE
Part No. Description Price
VDS-M 8-slot Mainframe with room for 2 8" floppies 800.00
VDS-II Single-Density Single-Sided Floppy Subsystem 22RR.00
VDS-IIMDD Mainframe above with 2 Double-Sided 6" floppies,
double-density interface, CP/M , Tarbell BASIC 2999.00
MEM-3 2K-ASM 32K fully-buffered static memory A&T 725.00
MEM-16K-ASM 16K fully-buffered static memory A&T *40.00
MEM-OK-ASM Fully-buf f ered static board without memory IC's 240.00
CI-KIT 1500 baud bi-phase Cassette Interface Kit 120.00
Cl- ASM 1500 baud bi-phase Cassette Interface A&T 175.00
FDI-KIT Universal Single-Density Floppy Interface Kit 225-.00
FDI-ASM Universal Single-Density Floppy Interface A&T 325.00
DD-ASM Double-Density DMA Floppy Disk Interface A&T 495.00
ju^ispRudent
computeRisr"
DISCLOSING INVENTIONS TO EMPLOYERS:
WHY IT’S IN THE EMPLOYEE’S INTEREST
There are numerous reasons for submitting a disclosure on an in-
vention, each of which may affect the employee in one way or
another, and all of which have significance to the employer.
Disclosure by the employee-inventor is the simplest and cheapest
way for the employer to identify those inventions that he may want to
patent. A patent can be a significant company asset. It enhances a
company’s competitive position, and can be beneficial to an em-
ployee’s position in the company.
From a competitive standpoint, the possibility of a suit for patent
infringement against another company could very well result in a
competitor expanding funds to design around the patented develop-
ment rather than taking the risk of infringing the patent. Thus, addi-
tional expense is incurred by such a competitor in designing around,
preventing him from getting a free ride on a company’s investment
and technical expertise. This advantage may help to secure an order
or boost sales of a product related to an employee’s area of technical
expertise.
Another advantage is the defensive trading position against other
patent owners. Cross-license agreements may allow a company to
enter the market at a lower cost than might otherwise be possible.
The trading value of patents, particularly in new technologies, can
result in lower royalties or in the elimination of patent royalties that
might otherwise have to be paid. Similarly, the company may be
able to enter a market that it might not otherwise have entered
without a very substantial investment for designing around the
patents of others. This could easily spur development in a tech-
nology to which the employee’s expertise relates.
Patents provide protection to the company against the issuance of
a patent to another on the same development. This is usually referred
to as protecting the right to use. Delaying disclosure could result in
someone else getting a patent. That would not be in either the
employee’s or the company’s interest.
TARBELL HAS HIGH-QUALITY 808C/Z80 SOFTWARL
Part No. Description Price
CPM-1.4 Floppy Disk Operating System for our interfaces 100.00
CPM-2.0 Extended Version of above Operating System 150.00
MPM Multi-User Version of above Operating System 400.00
TBAS-CAS Tarbell Cassette BASIC (uses 24k) 72.00
TBAS-DSK Tarbell Disk BASIC (uses 24k) 72.00
SPLR KLH Systems Spooler for CP/M 1.4 on disk 70.00
FAST Screen-Oriented Editor/Assembler for CP/M 100.00
TELE-COM Telecommunications Support System 195.00
POLYVUE Screen-Oriented CP/M Editor 135.00
PASCAL/MT Meta-Tech Pascal Compiler for CP/M 99.95
Prices are subject to change without notice.
CP/M is a registered trademark of Digital Research.
950 Dovlen Place, Suite B
Carson, California 90746
(213) 538-4251
(213) 538 2254
CIRCLE INQUIRY NO. 66
Patents also provide a basis for royalty income. There are occa-
sions when it is economically advantageous to license someone else
to make, use, or sell the product on which a company has a patent.
When this is done, it is usually in a product area in which the com-
pany has not traditionally participated and has not made the invest-
ment required to enter that field. Thus, patent licensing gives a com-
pany the opportunity to earn income by way of royalties in a product
area in which it might not otherwise have participated.
Finally, the establishment of a portfolio of patents on a particular
product, or in a particular technology, makes it more difficult for a
competitor to design around. The degree of commercial success in
a particular product area may be increased if a number of patents are
obtained on various inventions used in a product. This increases the
economic burden to which competitors are put, in order to compete
with a company without running the risk of infringing a patent.
Thus, in the best interests of all concerned, employees should
submit disclosures on their inventions. The name of the game is
competition. A company can legally obtain a competitive edge
through the patent system, and can also offer increased opportuni-
ties for its employees. □
28 INTERFACE AGE
JUNE 1980
new from..
HflRDSI
6 SOUTH ST., MILFORD, NH 03055
ATARI
A Warnpr
Communications Company o
* r \ r a r ^ » \w * r w * r
i-m5si®>
TO ORDER TOLL-FREE
1 - 800 - 258-1790
(In N.H. call 873-5144)
ATARI 800 (list 1080 . 00 ) 875.00
ATARI 400 (list 630 . 00 ) 515.00
810 DISK DRIVE ( 699 . 95 ) .... 565.00
820 40-COLUMN PRINTER
(list 599 . 95 ) 470.00
410 PROGRAM RECORDER
(list 89.95) 65.00
JOYSTICK CONTROLLERS . .18.95
PADDLE CONTROLLERS ...18.95
ATARI 850 I NTERFACE . to be announced
ATARI 830 MODEM . . . . to be announced
ATARI 825 PRINTER . . . . to be announced
JUNE 1980
CIRCLE INQUIRY NO. 33
INTERFACE AGE 29
C-10
50 FT.
SHORT
CASSETTES
Qty. Price
1 $1.00
10 $ 0.75
50 $ 0.65
Premium tape and cassettes acclaimed
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puter users. Price includes labels, cas-
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and M/C orders accepted. California
residents add sales tax. Phone (415)
968-1604.
MICROSETTE CO.
475 Ellis Street
Mt. View, CA 94043
CIRCLE INQUIRY NO. 48
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Finally your Apple II or Apple Plus can have low
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m.
BAKER'S
GAME
CORNER
Raise your hand if you have Programmer’s Aid #1 in your Apple
II. Have you tried to use its music? Well, today you will. This month,
our program is called PLAYER PIANO. It uses the musical notation
developed by Dick Ainsworth of The Image Producers for Bally
BASIC and APF BASIC.
Player Piano isn’t a game, toy, or even pure entertainment. It is a
serious attempt at using a computer to play music. But it is fun, and
it does show off some of the musical potential in Apple’s Program-
mer’s Aid #1 .
MUSICAL NOTATION
Player Piano uses the basic structure of the musical notation. Pro-
grammer’s Aid #1 doesn’t support multiple voices, a large number
of octaves, or the creation of note envelopes. The notes of the C ma-
jor scale are 1 through 7. On the Apple II, the octave immediately
below middle C is the default.
Figure 1. The musical scale: First row of numbers is
Programmer’s Aid #Ts own internal pitch notation.
The second row is our song notation.
Figure 1 shows the four octaves supported by Programmer’s Aid
#1 . The bottom row written between the staves is the standard nota-
tion. By itself, you can’t play the tune. You need to see each note on
the staff to know its octave. The upper row is the pitch notation
needed by Programmer’s Aid #1. Translating a song from sheet
music to this notation is time consuming.
Here are three songs written using Player Piano’s notation. Zeros
extend a note and spaces are rests. See if you can recognize them
before reading on:
3212333 222 355
144557641445560
660367030* 17* 1 *2*107
The first is “Mary Had a Little Lamb.’’ Next is “Lemon Tree.” Last
is “O Come, All Ye Faithful.”
Here is a summary of the rules for the basic notation:
• 1 through 7 are the notes of the C major scale
•use * to go up an octave
30 INTERFACE AGE
CIRCLE INQUIRY NO. 43
JUNE 1980
•use / to go down an octave
•use - for a flat note
•use + for a sharp
•use 0 to extend a note
•use a blank for a rest
USING PLAYER PIANO
I have provided several songs for you to play. Run Player Piano
and it will ask you to type in a song. Use as many lines as necessary
to enter it. When done, enter an empty line. After a brief pause, your
song will play. You can play it as many times as you want, or you
can enter a new song.
It is easy to create your own songs. That’s how I got some of those
here. If you can’t read sheet music, you may need someone’s help.
Find the shortest note in the piece. Suppose it is an eighth note
(which looks like this J* or n ). Then quarter notes will
have one zero after them and half notes will have three. Whole notes
will have seven. Here is the translation of this piece:
r»
H
XT
A
" 6-500607000 *30000000
If the piece sounds too fast or slow, change program line 230.
The lower the number, the faster the song. And don’t forget sharps
and flats. Your song won’t sound right if you forget to consider the
key it is written in.
THE PROGRAM
Lines 1 50 through 1 80 set up the constants used by Program-
mer’s Aid #1. MUSIC is the address of the music subroutine,
PITCH is where we place the note to be played, and TIME is where
we set the note’s length. Line 1 80 sets up the proper timbre of the
music. Read the Programmer’s Aid document for a description of
these locations.
I N $ is the person’s input string. A$ is where the program keeps
the entire song. Later, we convert the player piano’s notation into
pitch and time. These will be kept in the P and T arrays.
TT is the duration of our shortest note. Change this to speed up or
slow down the song. The B array contains the pitch values for the C
major scale.
From lines 340 through 400, the program builds the user’s song.
Lines 440 through 480 play the song as many times as desired.
The remainder of the program converts the player piano musical
notation into the computer’s.
For each note, we begin by assuming it will be the smallest length,
not a flat or sharp, and on the default octave. If a “/” is found, we sub-
tract the 1 2 pitch units of the tempered scale. If a is found, we add
the 12 half steps of the tempered scale. This handles changing oc-
taves. Likewise, “ + ” or creates a sharp by raising the note a
half step and creates a flat by lowering the note a half step.
Each time we find a zero in the string, we lengthen the note by
one time unit. Rests are handled by using a pitch of zero. The loop
on lines 960 through 1080 then plays the converted song.
ON YOUR OWN
This program doesn’t have a music editor in it. It doesn’t even
save your song. But it does have the building blocks. If you enjoy
playing music on your computer, it’s now up to you.D
LISTING 1
1* REn . . . PLflVB? FlfM . .
118 REM
m REM
m rem define mores
m REM
m
168 Pim=?67
178 TIME =786
188 POKE 765,32
DYNACOMP
Quality software for: Apple II Plus
TRS-80 (Level II)
North Star
All software is supplied with complete documentation which includes clear
explanations and examples. Each program will run with standard terminals (32
characters or wider) and within 16K program memory space. Except where
noted, all software is available on North Star diskette (North Star BASIC),
TRS-80 cassette (Level II) and Apple cassette {Applesoft BASIC). These pro-
grams are also available on PAPER TAPE (Microsoft BASIC).
FLIGHT SIMULATOR Price: $17.95 postpaid
(as described in SIMULATION, Volume II)
A realistic and extensive mathematical simulation of take-off, flight and landing. The
program utilizes aerodynamic equations and the characteristics of a real airfoil. You
can practice instrument approaches and navigation using radials and compass
headings. The more advanced flyer can also perform loops, half-rolls and similar
aerobatic maneuvers.
SIMULATION, Volume II (BYTE Publications): $6.00
V ALDEZ Price: $14.95 postpaid
A simulation of supertanker navigation in the Prince William Sound and Valdez
Narrows. The program uses an extensive 256X256 element radar map and employs
physical models of ship response and tidal patterns. Chart your own course through
ship and iceberg traffic. Any standard terminal may be used for display.
BRIDGE 2.0 Price: $17.95 postpaid
An all-inclusive version of this most popular of card games. This program both BIDS
and PLAYS either contract or duplicate bridge. Depending on the contract, your com-
puter opponents will either play the offense OR defense. If you bid too high the com-
puter will double your contract! BRIDGE 2.0 provides challenging entertainment for
advanced players and is an excellent learning tool for the bridge novice.
HEARTS 1.5 Price: $14.95 postpaid
An exciting and entertaining computer version of this popular card game. Hearts is a
trick-oriented game in which the purpose is not to take any hearts or the queen of
spades. Play against two computer opponents who are armed with hard-to-beat play-
ing strategies.
DATA SMOOTHER Price: $14.95 postpaid
This special data smoothing program may be used to rapidly derive useful information
from noisy business and engineering data which are equally spaced. The software
features choice in degree and range of fit, as well as smoothed first and second
derivative calculation. Also included is automatic plotting of the input data and
smoothed results.
FOURIER ANALYZER Price: $14.95 postpaid
Use this program to examine the frequency spectra of limited duration signals. The
program features automatic scaling and plotting of the input data and results. Prac-
tical applications include the analysis of complicated patterns in such fields as elec-
tronics, communications and business.
MAIL LIST I Price: $18.95 postpaid (available for North Star only)
A many-featured mailing list program which searches through your customer list by
user-defined product code, customer name or Zip Code. Entries to the list can be con-
veniently added or deleted and the printout format allows the use of standard size
address labels. Each diskette can store more than 1000 entries.
MAIL LIST SERVICE
DYNACOMP can provide you with a customized mail list service. Your customer/
patient records are placed in a master computer file and you are provided with address-
ed, self-adhesive labels for your mailings. These labels may be sorted by name. Zip
Code, date, or other identifiers. Write for further details and a price schedule.
TEXT EDITOR I (Letter Writer) Price: $14.95 postpaid
An easy to use, line-oriented text editor which provides variable line widths and simple
paragraph indexing. This text editor is ideally suited for composing letters and is quite
capable of handling much larger jobs.
GAMES PACK I Price: $10.95 postpaid
Seven entertaining games for less than a dollar a kilobyte! Play CATAPULT, CRAPS,
SWITCH, HORSERACE, SLOT MACHINE, BLACKJACK and LUNAR
LANDER. This is an excellent and economical way to start your games library.
All orders are processed within 48 hours. Please enclose payment with order. If paying by
MASTER CHARGE or VISA, include all numbers on card. Foreign orders add 10% for
shipping and handling.
Write for detailed descriptions of these and other programs available from DYNACOMP.
DYNACOMP
P.O. Box 162
Webster, New York, 14580
New York State residents please add 7% NYS sales tax
JUNE 1980
CIRCLE INQUIRY NO. 23
INTERFACE AGE 31
for TRS-80 II. Compucolor II.
&PET
EVERYTHING YOU NEED
TO BRING YOUR BASIC
PROGRAMS TO LIFE WITH
SOUND!
SOUN DWARE is a complete package:
YOU GET A SPEAKER /AMPLI-
FIER UNIT complete with connectors.
No wiring or soldering. Just plug in!
YOU GET A DEMO PROGRAM with
a variety of sample sound effects—
sirens, laser sounds, tunes!
YOU GET A COMPOSER PRO-
GRAM to help you create your own
original sound effects. Fun for all ages!
YOU GET AN INSTRUCTION
BOOKLET that tell you how to insert
sound into your programs. 1 year
warranty.
Complete Programs
Package or & Booklet
^ALL PETS & TRS-80 II $29.95 $14.95
Compucolor II $39.95 $19.95
SEND FOR FREE CATALOG OF
GAMES FOR PET & COMPUCOLOR!!
SEE YOUR DEALER TODAY! Or order direct from CAP by phone or
mail. VISA & MasterCharge orders include expiration date. Add $1
postage & handling per order. $3 for air or COD. Arizona residents
add tax.
CAP Electronics 8462 Hillwood Ln.. Suite 4. Tucson. A Z 85715 (602) 2% 4078
CIRCLE INQUIRY NO. 8
ANNOUNCING:
NEW!
MICROSTAT
A complete statistics package for business, scientific,
education and research work. No other package has
the features of MICROSTAT. For example:
• File oriented with COMPLETE editing
• A Data Management Subsystem for editing, sort-
ing, ranking, lagging, data file transfers PLUS 1 1 data
transformations (e.g., linear, reciprocal, exponential,
etc.) • Frequency distributions * Simple and multiple
regression • Time series (including exponential smooth-
ing) • 11 Non-parametric tests * Crosstabs/ Chi-square
• Factorials (up to 1,000,000!), permutations, combinations
• 8 Probability distributions • Scatterplots
• Hypothesis test (Mean, proportion) • AN0VA
(one and two-way) • Correlation • Plus many
other unique features
Users manual: $10.00 (credited towards purchase)
and includes sample data and printouts. Uses
NORTH STAR BASIC 32K of memory, one or two disk
drives (2 recommended). Printer optional. Price: $200.00
P.0. Box 68602
Indianapolis, IN 46268
Phone orders:
(317) 253-6828
m m mm T(MhB(7),H$m.mw
m RBf
m sm set TEm notes
m reh
238 17=25
2# oam
258 B(2>=2 2
m B(3)=24
m B(4)=25
ffl B(5)-27
m Bi6 )- 25
m B(7)=31
318 REH
328 RBf f£CEPT USER'S SONS
m REH
J48 m= ne
358 PRINT ‘EHm Sflifi 1 WILL ACCEPT INPUT UNTIL”
M PRINT “m ENTER fiN EHPTr LINE . 3
m INPUT • ENTER SONS INt
388 IF IN$= aH I HEN 440
m m mmwm
m goto m
418 REH
428 REH m THE SM PS OFTEN AS DESIRED
428 REH
4# GOStS 566
m input *m it min
m IF THEN 440
4W IF m-W THEN M
488 GOTO 450
456 RBI
M REH
510 REH FlftV THE miC STRING
520 REH
538 REH
5 46 REH FIRST, mm TO THE CORRECT MISERS FOR PITCH AND TME”
55e REH
568 0CT=6
578 H0M
m J=1
5% FOR M TO LEN(Rf)
m T(1)=TT
SIS H$=Fi(Li)
628 IF Hf=V“ THEN 0l-T=0CT-12
88 IF THEN 0CT=0CT*12
648 IF H$= a :“ THEN CCMCM2
m IF H$= a t’‘ THEN HQMW+1
668 IF &=*; 8 THEN ffGWBP+1
678 IF «=»-* THEN NtMOlhl
m IF THEN 778
32 INTERFACE ACE
CIRCLE INQUIRY NO. 24
JUNE 1980
if ( Rscm)} mwm mm< m B s u )> then m
m if m*' • net m
718 REII
728 REM iUSJCnL RESTS HiWLED HERE
m Ptt)=8
7 ft GOTO m
m REM
768 REM UNGER NOTES HHNDL3 HERE
m t(M)-t(J-ihtt
m IF J(M))255 THEN T(j-l)=255
798 GOTO m
Em REM
818 REM NOTES f#M£P HERE.
828 REM NOTE = Bf££ NOTE + FLPJ/5HRRF. f miFlER + QCH¥E CHRNGE
m K= mHt)-128-48
m K=Bmm+QC- t
m IF Dm WN k-58
m IF m THEN K-l
878 PCJ.NC
m J=M
m MOM
m ocr=g
m NEHT !
928 REM
938 REM PLflV THE CONVERTED MR
W REM
m J=J-i
968 FOR J=i TO J
970 POKE PITCH. PCD
988 POKE TIMS TCI)
sse cm. fwsic
m NEXT I
1818 RETURN
LISTING 2: Marine’s Hymn
1350505050
604060405006
500*15034
50*1760406*100
505042001000
500000135050
001350505050
5050500*15034
500*150345050
500050006000
4200100000*17
7000*1000
AUTHORIZED
Radio /haeH
DEALER A301
COMPUTER SPECIALISTS
10 %
DISCOUNT
Off
List
64 K 1 Drive
$3499.00
Popular 16K Level 1 1 System $ 722.00
26-1145 RS-232 Board 84.00
26-1140 "O" K Interface 254.00
26-1 160 Mini Disk 424.00
26-1171 Telephone Modem 169.00
Fast 100 CPS Centronics 730 Printer 750.00
Highly Reliable Lobo5'/4" Drives 375.00
Versatile Lobo Interface, 8" Drives
and IMI Hard Drives Call For Prices
15%
DISCOUNT
Off
List
4K Level II
$527.00
No Taxes on Out Of
State Shipments
Immediate Shipment
From Stock.
MICRO MANAGEMENT SYSTEMS, INC.
DOWNTOWN PLAZA SHOPPING CENTER
1 15 C SECOND AVE. S.W.
CAIRO, GEORGIA31728
912-377-7120
Full Factory Warranty
on All Items Sold.
VISA, Master Charge
and COD's, Add 3 %
JUNE 1980
CIRCLE INQUIRY NO. 47
INTERFACE ACE 33
SPECIALIZING
IN
QUALITY
MICRO-
COMPUTER
HARDWARE
INDUSTRIAL
EDUCATIONAL
SMALL BUSINESS
PERSONAL
ELECTRONIC
CONTROL
TECHNOLOGY
763 RAMSEY AVE.
HILLSIDE, N.J. 07205
( 201 ) 686-8080
RACKMOUNT CARD CAGES
POWER SUPPLIES , CPUs ,
MEMORY , OEM VARIATIONS
BUILDING BLOCKS FOR
MICROCOMPUTER SYSTEMS,
CONTROL & TEST EQUIPMENT
R 2 I/O
2K ROM 2 K RAM
3 SERIAL PORTS 1 PARALLEL PORT
TABLE TOP MAINFRAMES
CIRCLE INQUIRY NO. 25
> 159.95
OSDORME BUSINESS
SOFTWARE
The full, complete OGA pockages — supported — in source form
Enhonced CRT routines eose instollotion interfaces available for
many common terminals. Auto-input feature eliminates pressing
return key Some programs speeded up. Cosh reword for finding
bugs — users updated to new releases. Other complementary
business packages under development — custom programming
available (references)
Requires CP/M and CDASIC2. Available m either 8 single-density
soft sectored or 5 Vi double-density NorthStor format (TRS-80 Mod
II™ users — order the 8 version.) All users required to sign licensing
agreement, attractive dealer discount schedule available on
request
Prices: Payroll with Cost Accounting $ 59 95
Accounts Payable ond Accounts Receivable (both) $ 59.95
General Ledger with Cosh Journal $ 59.95
All Packages — Complete $159.95
Manuals not included in package price — add $20 /manual
desired
To order coll: (206) 542-8370
Or write: VANDATA • 17541 Stone Ave N • Seattle WA 98133
COD/ VISA / MC Welcome — WA state residents odd 5 4% soles tax TIXS-80 is
a registered trademark of Radio Shock
LISTING 3: Amazing Grace
20500075700060
70*2007*275000
5000302000205000
2300553200020
75 700060*2000
5000757000605000
LISTING 4: Bagpipes
405654-70*2*106
46*2*164505505
406654502300
46*2*16460*1
405654-70*2*106
*20*3*4*2*1
*406654504401
654605400
46*2*1 64606605
LISTING 5: Frankie and Johnny
1236053010100000
1236053010000010
456* 10*260*10
*100067*10*1*17060
503030-3020000000
blanks -►^65650010000000000000
LISTING 6: Greensleeves
30500060700+170
6000+402003+40500030
300+230+^000+20/700030
500060700*1706000+40
2003+40500+430+200+1 20
300030300000*200000*200
+*1706000+402003+40
500030300+230+4000
+20/700000*200000*200
+*1 706000+402003+400
500030+200+1 203000003000
34 INTERFACE ACE
CIRCLE INQUIRY NO. 70
JUNE 1980
Diagnostics I
for CP/M* & TRSDOS
DIAGNOSTICS I will really put your system through its paces. Each
test is exhaustive and thorough. The tests include:
•Memory Test
•Disk Test
■Printer Test
■CPU Test (;8080f/8085/Z8Q)
■CRT Test
To our knowledge, this is the first CPU test available for 8080/Z80
CPU’s. Many times transient problems, usually blamed on bad
memory, are really CPU errors.
A good set of diagnostics is an indispensable addition to your
program library even if your system is working fine. Hours have been
wasted trying to track down a “program bug” when actually
hardware was to blame!
DIAGNOSTICS I also allows you to be confident of your system.
This can be critical when file merges or sorts and backups
are involved. You want to be as sure of your computer as possible
during these critical times. Running DIAGNOSTICS I prior to
these and other important functions helps to insure that your
system is operating at peak performance.
DIAGNOSTICS I is supplied on discette with a complete
users manual.
DIAGNOSTICS I: $50.00
Sofoeday your computer is going to break; even the most reliable
computer systems "go down”. Often, finding exactly what is
wrong can account for the most time consuming part of repairing
the system, and the longer the system is down, the more
money you lose.
DIAGNOSTICS I is a complete program package designed to check
every major area of your computer, detect errors, and find the
cause of most common computer malfunctions, often before they
become serious. For years, large installations have run daily
or weekly diagnostic routines as a part of normal system
maintenance and check-out procedures.
Requires: 24K CP/M: 16K disc for TRS-80
formats: CP/M 8" SOFT SECTORED. NORTHSTAR CP/M
AND TRS-80 DOS
All Orders and General Information:
SUPERSOFT ASSOCIATES
P.0. BOX 1628
CHAMPAIGN, IL 61820
(217) 344-7596
Technical Hot Line: (217) 384-0847
(answered only when technician is available)
DIAGNOSTICS I is designed to provide that kind of performance
testing for 8080/Z80 micro computers.
Give your computer a “physical” today!
Manual:
$15.00
MATHEMATICIAN
By Dr. Alfred Adler
NUMERICAL INTEGRATION OF
TRAJECTORY EQUATIONS
Review of Integration
Last month we explored the general subject of integration. We used
a very simple equation to demonstrate the analytical process of in-
tegration, and pointed out that if an equation is not available, as in
the case of experimental data, any necessary integrations must be
performed numerically.
The subject of numerical integration was examined and two of the
simplest forms, the Trapezoidal Rule and Simpson’s Rule, were
looked at in detail. Program NUMERINT, which facilitates com-
parisons between these two methods, was presented along with a
number of sample runs.
It was concluded that, in the majority of cases, Simpson’s Rule
gives more accurate results in much less time than the Trapezoidal
Rule. Under certain circumstances, however, Simpson’s Rule may
present no advantage and might possibly even introduce difficulties.
As shown in last month’s column, simple equations can usually
be integrated analytically. The result, of course, is another equation.
Everything is very convenient and tidy. What was not stated last
month, however, is that there exist many types of neat and tidy equa-
tions that cannot be integrated analytically. Only certain forms are in-
tegrate, and an equation not fitting the limited number of possible
molds is generally not integrable. Having shown in last month’s col-
umn how to use numerical integration to find the area under a
curve, it would be instructive to continue by showing how to solve a
differential equation numerically.
Trajectory Equations
Among the many types of differential equations that are not easily
integrable are the equations describing the trajectory of an object
under the influence of gravity, thrust, and aerodynamic forces. If
aerodynamic forces are either ignored or simulated in a simplified
manner, and if one or two of a variety of other simplifications are
made, the equations of motion can be integrated analytically.
T
Figure 1. Atmospheric forces on an object in flight.
Whether this results in a neat little package or a mess depends on
the details of the simplifications. We are concerned with analytical
integration of these equations since we want to be able to determine
the accuracy of the numerical integration procedure used. We must
therefore abridge the equations to the point where they can be inte-
grated analytically. In this article, we shall integrate two abridged ver-
sions of the trajectory equations. One is very abridged, the other
about as little as can still be reasonably handled analytically. A deter-
mination of the accuracy of the numerical equation will be made and
the difficulties and possible remedies explored.
Figure 1 shows the forces on an object in flight in the atmosphere,
under the influence of gravity, thrust, and aerodynamic forces. The
equations of motion, parallel and perpendicular to the flight path,
along with the required auxiliary equations, are shown in figure 2.
These equations already include many simplifying assumptions,
among them a spherical nonrotating earth, two-dimensional motion,
stepwise constant thrust, aerodynamic forces that act at the vehicle
center of mass, etc. These equations are presented primarily to give
the reader an idea of what is involved in determining the trajectory of
even a non-winged vehicle (a winged vehicle is far more complex),
even under the simplifying assumptions stated. These equations, of
course, must be integrated numerically.
m = Tcos(a+6) - mgsinv - D
mV ^ = L + Tsin(a+6 ) - mgcosy +
mV^cosy
R + h
T = T e —
1 sp 8 dt
GM
6 ~ (R + h) z
dm
r = R + JVsiny dt
Range = cosy dt
where G = Universal gravitational constant
M = mass of Earth
R = radius of Earth
r = distance from center of Earth
h = altitude above surface of Earth
I g p = specific impulse of propellant
T = thrust
V = velocity
m = mass of vehicle
Y = flight path angle with local horizontal
D = Drag
L = Lift
subscript o = initial condition
Figure 2. Equations of motion, parallel and perpendi-
cular to the flight path.
Let us first abridge the equations until we have a set that are easily
integrated analytically. We make the following assumptions.
1 . Lift and drag equal zero.
2. Thrust equals zero.
3. The flight range is small compared to the radius of the earth.
This permits the assumption that the earth is flat, which implies
that g is constant. This limits the flight altitudes to under
about 100 miles.
4. The flight path is vertical.
Having made these assumptions, the equations reduce to those
presented in figure 3. These are, of course, the familiar, so-called
falling body equations given in every high school physics text. They
are, however, valid for motion in either direction.
36 INTERFACE AGE
JUNE 1980
H--*
dt
(1)
v = HE = v o ' ^
(2)
h = h + V t
o o
- \ St 2
(3)
Figure 3. Simplified flight path equations.
Since the equations for velocity and altitude in figure 3 were ob-
tained analytically by successive integration of the first equation, the
results they give are accurate and will be considered ‘correct’ within
the limits of our simplifying assumptions. In order to perform
numerical integration on the first equation, it must be recast. The d
in all these equations implied an infinitely small increment. Thus
dh/dt means an infinitely small increment in h, divided by an infi-
nitely small increment in t. This quotient represents the rate of
change of altitude with respect to time and is, of course, the vertical
velocity. We cannot represent an infinitely small quantity on a digital
computer. Therefore the equations must be written in a form that
eliminates the need for infinitesimals. We can, of course, always take
a finite number of finite steps instead of an infinite number of infi-
nitesimal steps. The larger the finite size steps, however, the greater
the error in the results. That is exactly what we will do. Using the up-
per case delta to represent a finite increment, we can rewrite the
equations in figure 3.
Equation 1 is rewritten as equation (4) in figure 4. The latter states
that the finite increment in vertical velocity equals minus g times the
finite increment in time. This can be handled by a digital computer.
Using the equations of figure 4, we proceed stepwise. Equation (4)
yields the increment in velocity. By adding that to the previous
velocity, we obtain an updated value, equation (5). Using this up-
dated velocity we obtain the increment in altitude from equation (6).
This, of course, assumes that V is constant during each time incre-
ment, and that is where the error arises. If the increment is in-
finitesimal, as it is in the analytic solution, this is correct, and we
have zero error. But if the increment is larger (finite), it is in general
not correct, and we have an error. Obviously, the smaller the steps
taken (timewise, in this case) the smaller the error. Of course, in the
event that the velocity actually is constant during the time increment,
the numerical integration would be exact. It turns out that the incre-
ment in velocity given by equation (4) is exact, regardless of step
size, since g is constant. It is for this reason that equation (5) yields
exact results, regardless of step size (see the sample runs). Finally,
adding the increment in altitude from equation (6) to the previous
altitude, we obtain an updated value (see equation (7)).
Av = = -gAt
(4)
V n + 1 = V n + AV
(5)
Ah = vAt
(6)
h n + 1 = % + Ah
(7)
Figure 4. Finite increment of simplified flight path
equations.
Program VERTRAJ1
Program VERTRAJ1 presents tabulated values of V and h from
equations (5) and (7) for comparison against the values from equa-
tions (2) and (3). The computational sequence discussed above is
followed exactly. The user is asked to input initial values of altitude
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CIRCLE INQUIRY NO. 68
INTERFACE ACE 37
and velocity, and then must choose the integrating interval, that is
the time increment, and the print interval. A listing of program VER-
TRAJ1 is given in figure 5.
10 REM | | | I I I I I I I I I I I I I I I I I I I I I I II I I i I I I I I I I I I I I I I I I I I I I I I I I I i I
20 REM
30 REM llllllllllllll Proqram VERTRAJ 1 I I I I I I
40 REM
50 REM I I I I I I I I I I I I Written by - Alfred A. Adler, Ph.D. I 'I I
60 REM
70 REM I I I I I I I I I- 1 I II I I Version 1.0 - January 1980 I I | I I I I
80 REM
85 DIM F ( 366 )
88 P2=6. 2831853
95 1
98 REM ****** INPUT DATA ******
100 INPUT“Initial altitude ?",H0
110 INPUT"Initial velocity ?",V0
120 INPUT'What is the integrating interval ?'‘,T1
130 INPUT"What is the print interval ?",T2
135 i
140 G=32 .174
145 REM ****** INITIALIZE ******
150 H=H0\V=V0\Z=0
160 l TAB( 6 ) , “T" , TAB( 14 ) , "H ( N . I . ) " , TAB ( 26 ) , "H ( ANAL ) " , TAB ( 38 ) ,
170 1"V ( N . I . ) “ , TAB ( 50 ) , *' V (ANAL)"
175 REM ****** TRAJECTORY COMPUTATION ******
180 FOR T=0 TO 1000 STEP T1
190 REM ****** ANALYTIC ******
200 V9=V0-G*T \REM V9=V (ANAL)
210 H9=H0+V0*T-G/2*T?2 \REM H9=H (ANAL)
220 IF T/T2 < > I NT ( T/T2 ) THEN 250
230 1 %9F2,T, %12F2,H,H9,V,V9
240 IF Z=1 THEN EXIT 95
245 REM ****** NUMERIC ******
250 V3=-G*T1 \REM V3=DELTA V (N.I.)
260 V=V+V3
270 H3=V*T1 \REM H3=DELTA H (N.I.)
280 H=H+H3
290 IF V<0 THEN IF H<0 THEN Z=1
300 NEXT
READY
Figure 5. Program VERTRAJ1
Sample Runs on VERTRAJ1
Sample runs on program VERTRAJ 1 are presented in figures 6
and 7. In figure 6, we integrate every 1 second. The numerically in-
tegrated values of V are exact for reasons already discussed. The
numerical values of h, however, contain considerable error. In an ef-
fort to reduce this error, we integrate on a much smaller time incre-
ment, as shown in figure 7. These values of h are much more ac-
curate, possibly satisfactory for some purposes. But at what cost?
The run in figure 6 took 9 seponds, but the run in figure 7 took 1 00
times that long (16 minutes). That is intolerable if many runs are to
be made.
Initial altitude 7500
Initial velocity 71000
What is the integrating
interval 71
What is the print interval 710
T
H (N.I. )
H (ANAL)
V (N.I . )
V (ANAL)
• 00
500.00
500.00
1000.00
1000.00
10.00
8730.43
8891.30
678.26
678.26
20.00
13743.46
14065.20
356.52
356.52
30.00
15539.09
16021.70
34.78
34.78
40.00
14117.32
14760.80
-286.96
-286.96
50.00
9478.15
10282.50
-608.70
-608.70
60.00
1621.58
2586.80
-930.44
-930.44
70.00
-9452.39
-8326.30
-1252.18
-1252.18
Initial altitude 7
STOP IN LINE
READY
100
Figure 6.
Program VERTRAJ1 integrating every
1 second
Initial altitude 7500
Initial velocity 71000
What is the integrating interval 7.01
What is the print interval 710
T
H (N.I. )
H (ANAL)
V (N.I. )
V (ANAL)
.00
500.00
500.00
1000.00
1000.00
10.00
8889.69
8891.30
678.26
678.26
20.00
14062.00
14065.20
356.52
356.52
30.00
16016.89
16021.70
34.78
34.78
40.00
14754.37
14760.80
-286.96
-286.96
50.00
10274.45
10282.50
-608.70
-608.70
60.00
2577.15
2586.80
-930.44
-930.44
70.00
-8337.44
-8326.30
-1252.15
-1252.18
Initial altitude 7
STOP IN LINE 100
READY
Figure 7. Program VERTRAJ1 with smaller time
increment.
Recall that the main source of error is that the increment in h is
computed in equation (6) on the assumption that V is constant dur-
ing the integration interval. This V incidentally is the updated value,
which means that it is the value at the end of the time interval. That
explains why h is too low on the way up and also on the way down.
Suppose we save the old value of V, that is the value at the end of
the previous interval, average that with the value from equation (5),
and use the average value in equation (6). This should improve the
accuracy of the numerical integration.
Program VERTRAJ2
Program VERTRAJ2 is simply VERTRAJ 1 modified as discussed
above. In the interest of economy, we present only that part of the
listing below REM ****** NUMERIC* ***** , see figure 8. The re-
mainder of the listing is identical to that shown in figure 7.
245
REM ****** NUMERIC
******
250
V3=-G*T1 \REM V3=DELTA V
(N.I. )
255
V4=V
260
V=V+V3
265
V5=( V4+V ) / 2
270
H3=V5*T1 \REM H3=DELTA H
(N.I. )
280
H=H+H3
290
IF V<0 THEN IF H<0 THEN Z
=1
300
NEXT
READY
BYE
+
Figure 8. Program VERTRAJ2
Sample Runs on VERTRAJ2
We repeat the run of figure 6 using the modified program, see
figure 9. It turns out that this is the only sample run required which,
incidentally, took only 1 1 seconds. The modification permits pro-
gram VERTRAJ2 to give numerical integration results that are exact,
regardless of how large an integrating interval is used, as subsequent
runs demonstrated. How can this be? Examination of the equations
reveals that the velocity is a linear function of time. Therefore, multi-
plying the average velocity over the time interval, by the time inter-
val, yields the exact value for the change in altitude. How fortunate.
Initial altitude 7500
Initial velocity 71000
What is the integrating interval 71
What is the print interval 710
T
H (N.I. )
H (ANAL)
V (N.I . )
V (ANAL)
.00
500.00
500.00
1000.00
1000.00
10.00
8891.30
8891.30
678.26
678.26
20.00
14065.20
14065.20
356.52
356.52
30.00
16021.70
16021.70
34.78
34.78
40.00
14760.80
14760.80
-286.96
-286.96
50.00
10282.50
10282.50
-608.70
-608.70
60.00
2586.80
2586.80
-930.44
-930.44
70.00
-8326.30
-8326.30
-1252.18
-1252.18
Initial altitude 7
Figure 9. Program VERTRAJ2 using run of figure 6.
Less Abridged Equations
Our good fortune with the previous set of equations was due to
the very severe constraints put on the trajectory. Exact solutions by
numerical integration are not an everyday occurrence. This time we
will formulate equations for a more realistic trajectory, while still re-
maining sufficiently constrained that they can still be solved analytic-
ally. This is an absolute requirement if we are to determine the ac-
curacy of the integration.
Again starting with the equations in figure 2, we modify the
previous assumptions as follows.
1 . Lift equals zero, but drag = K* V*Xdot, where K is the product
of the drag coefficient, the reference area, and one-half the air
density. Xdot is the horizontal component of the velocity.
4. The flight path is non-vertical, see text.
With these assumptions, the equations reduce to those presented in
figure 10. They are significantly more complex than the previous
set. The reason incidentally for the drag assumption, number 1
38 INTERFACE ACE
JUNE 1980
above, is that the correct formulation D = K*V A 2 produces a very
messy analytic solution. For trajectories with flight path angles not
exceeding 45 °, Xdot is not too radically different from V, and the
results are surprisingly good. The assumption of constant air dens-
ity, of course, requires that either the trajectory be entirely at high
altitude, or that the altitude change be small. This again requires a
flat trajectory. At lower altitudes the accuracy can be improved con-
siderably by using a value for air density equal to that at the initial alti-
tude minus one third of the difference between the value at the initial
altitude and the value at the apogee (the highest point) of a trajectory
computed letting density equal the value at the initial altitude. This is
noted in the heading of the listing of program TRAJ/GD1.
d 2 >
d x _ -KVx x
m V
d h _ -KVx h
m V
d 2 h
dx
dt
/ _ dh
h - dt '
1 + - * t
ra o
= Xdot
- Q ( 2 + - it ) + h_
2 V, mo/ o
Hdot
1 + £ * n t
m o
( 8 )
(9)
( 10 )
(ID
x i + 5 V>
( 12 )
h= (k * + ? ? f*) in(i + ■ *» t) ■ f(i " + ^ + h ° (13)
-
(14)
Y = arctangent j (15)
Figure 10. Further modifications on flight path
equations.
* _ - K*JSA t
x W ^
(16)
h _
n V W
s)At
(17)
X = X + Ax
(18)
h = h + Ah
(19)
Ax = x At
(20)
Ah = h At
(21)
x = x + Ax
(22)
h = h +Ah
(23)
,, U2 , .2
V = -y h + x
(24)
e
Y = arctangent 4
X
(25)
Figure 11. Numerical modifications of flight path
equations.
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JUNE 1980
CIRCLE INQUIRY NO. 55
INTERFACE ACE 39
Examination of the equations in figure 1 0 shows that equations
(12) and (13) become indeterminate if K, that is, drag equals zero.
Also, equation (1 3) becomes indeterminate if Xdot equals zero, that
is for vertical flight. Suitable error returns have been put into the pro-
gram, but all possibilities have NOT been checked out.
We have modified the equations of figure 10 for numerical inte-
gration exactly as we modified those of figure 3. The results are
presented in figure 1 1 .
Program TRAJ/GD1
Program TRAJ/GD 1 presents tabulated values of V, h, flight path
angle (gamma), and range (X) from equations (24), (23), (25), and
(22), for comparison against the values from equations (14), (13),
(15), and (12). The computational sequence is exactly as in pro-
gram VERTRAJ1. The user is asked to input initial values of alti-
tude, velocity, and gamma. If a zero value is . input for velocity or
gamma, an error return appears and the user is then asked for the
‘drag-weight parameter’, C(D)*S/W, from which K will be deter-
mined. If a zero value is input another error return is touched off. In
this case, however, the computation of H(AN) and X(AN) is aborted
but the remainder of the calculation is continued. The reasons for
these error returns were discussed in the previous section. Finally
the integrating interval and the print interval are entered. A listing of
program TRSJ/GD1 is given in figure 12.
10 rem////////////////////////////////////////////////////////////////
20 REM
n T R A J / G D 1 //////////////
Prog
- Alfred A. Adler, Ph.D. ///////////
1.0 - January 1980 ///////////////
*“\1
30 REM//////////////
40 REM
50 REM//////////// Written by
60 REM
70 REM/////////////// Version
80 REM
190 G=32 .174
200 S=41 . 5E-6
202 R9=57. 29578
205 REM ****** INPUT DATA ******
210 INPUT” Initial altitude ?",H0
220 P= . 00 2 3 78* EXP ( -S*H0 )
230 INPUT" Initial velocity ?”,V0
235 IF V0=0 THEN 244
240 INPUT” Initial qamma ?" , GO
242 IF G0<=89.8 THEN 255
244 1 \ 1 "*** THE ANALYTICAL EQUATION FOR H BECOMES INDETERMINATE"
245 1" IF GAMMA=90 DG. ALSO THE DRAG ASSUMPTION IS NOT"
247 1" GOOD FOR HIGH ANGLE TRAJECTORIES. TRY AGAIN. *
248 IF V0=0 THEN 230
250 GOTO 240
255 INPUT "C ( D) *S/W = ?",D1
260 IF D1 < > 0 THEN 290
270 1\I"*** THE ANALYTICAL EQUATIONS FOR X AND H BECOME INDETERMINATE"
280 ! " IF DRAG=0. H ( AN ) AND X(AN) WILL NOT BE PRINTED.
290 C=D1*P/2*G
300 INPUT"What is the inteqratinq interval ?",T1
310 INPUT"What is the print interval ?",T2
320 REM ****** INITIALIZE ******
330 G1=G0/R9
340 G4=G0
350 X4=VO*COS(G1) \REM X4=Xdot
360 X8=X4 \REM X8=Xdot ( initial )
370 H4=V0*SIN(G1) \REM H4=Hdot
380 H8=H4 \REM H8=Hdot ( initial )
390 X=0\H=H0\V=V0\Z=0
4001
410 l TAB ( 2 ) , "T" , TAB ( 7 ) , "H ( NI ) ” , TAB ( 15 ) , ”H( AN ) " , TAB ( 22 ) ,
420 1 ”V(NI) ” , TAB (29) , " V( AN ) " , TAB ( 35 ) , "G ( NI ) ” , TAB ( 41 ) , H G(AN) ",
4 30 1 TAB ( 49 ) , "X( NI ) " , TAB ( 57 ) , ”X(AN)"
435 REM ****** TRAJECTORY COMPUTATION ******
440 FOR T=0 TO 1000 STEP T1
445 REM ****** ANALYTIC ******
450 L1=1+C*X8*T
460 X7=X8/L1 \REM X7=Xdot (ANAL)
470 H7=(-G*T/2*(1+L1 )+H8)/Ll \REM H7=Hdot (ANAL)
480 V9=SQRT ( X7 ? 2+H7 ? 2 ) \REM V9=V (ANAL)
490 IF H7<0 THEN V9=-V9
500 IF X7< >0 THEN 520
505 IF H7>0 THEN G9=90
508 IF H7=0 THEN G9=0
510 IF H7 <0 THEN G9=-90
515 GOTO 530
520 G9=ATN(H7/X7)*R9
530 L2=LOG ( LI )
540 IF D1=0 THEN 570
550 X9=L2/C \REM X9=X (ANAL) & H9=H (ANAL)
560 H9=(H8/X8/C+l/2/C?2*G/(X8:2) ) *L2-G*T/4* ( 2/C/X8+T ) +H0
570 IF T/T2 < > I NT ( T/T2 ) THEN 630
580 IF D1=0 THEN 610
590 1 %4F0 , T , %8F0 , H , H9 , % 7 F0 , V , V9 , %6F1 , G4 , G9 , %8F0 , X , X9
600 GOTO 620
610 I %4F0,T, %8F0,H, ” " , %7F0 , V , V9 , %6F1 , G4 , G9 , %8F0 , X, "
620 IF Z=1 THEN EXIT 180
625 REM ****** NUMERIC ******
630 X2=-C*X4?2*T1 \REM X2=DELTA Xdot (N.I.)
640 H2=(-C*X4*H4-G)*T1 \REM H2=DELTA Hdot (N.I.)
650 X4=X4+X2 \REM X4=Xdot (N.I.)
660 H4=H4+H2 \REM H4=Hdot (N.I.)
670 V=SQRT ( X4^ 2+H4? 2 )
680 IF H4 < 0 THEN V=-V
690 IF X4< >0 THEN 710
695 IF H4> 0 THEN G4=90
698 IF H4=0 THEN G4=0
700 IF H4 < 0 THEN G4=-90
705 GOTO 720
710 G4=ATN ( H4/X4 ) * R9
720 X3=X4*T1 \REM X3=DELTA X (N.I.)
730 H3=H4*T1 \REM H3= DELTA H (N.I.)
740 X-X+X3
750 H=H+H3
760 IF V<0 THEN IF H<0 THEN Z=1 _.
770 next Figure 12. Program TRAJ/GD1
READY
40 INTERFACE ACE
JUNE 1980
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CIRCLE INQUIRY NO. 19
INTERFACE AGE 41
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It is emphasized again that this program and the one following
have not been exhaustively checked for possible malfunctions. They
will not, however, give wrong answers with no warning. For exam-
ple, in order to get all the information desired on an 8/2 by 1 1 inch
page, the columns were crowded as much as possible. If very high
values of any of the variables are attained during the trajectory,
BASIC will abort the run and complain about a ‘format error’ in line
590 (or 610). These programs were designed to test numerical in-
tegration routines, not to compute trajectories, although within the
limits of the assumptions, the results are correct if the program runs
to completion with no apparent malfunctions.
Sample Runs on TRAJ/GD1
Again we repeat the run of figure 6 as closely as we can (as a
check, see figure 13). The fractional differences are due to the
slightly off vertical launch; otherwise everything checks. This run in-
cidentally took 63 seconds compared to only 9 seconds for the run
of figure 6 . We only added a bit of complication to the equations yet
the running time went up by a factor of 7. Since we are not any-
where near a set of equations that could even remotely be consid-
ered as realistic, it is apparent that large improvements must be
made in the integration schemes if reasonable times are to be
achieved for realistic equations.
Initial altitude 7500
Initial velocity 71000
Initial qamma 789.8
C(D)*S/W = 70
*** THE ANALYTICAL EQUATIONS FOR X AND H BECOME INDETERMINATE
IF DRAG=0 . H ( AN ) AND X(AN) WILL NOT BE PRINTED. ***
What is the integrating interval 71
What
is the
print interval
710
T
H(NI )
H( AN ) V ( NI )
V ( AN )
G ( NI ) G( AN )
X ( NI )
X ( AN )
0 .
500.
1000.
1000 .
89.8 89.8
0.
10 .
8730.
678.
678.
89.7 89.7
35.
20.
13743.
357.
357.
89.4 89.4
70.
30.
15539.
35.
35.
84.3 84.3
105.
40.
14117.
-287.
-287.
-89.3 -89.3
140.
50.
9478.
-609.
-609.
-89.7 -8S*.7
175.
60.
1621.
-930.
-930.
-89.8 -89.8
209.
70.
-9453.
-1252.
-1252.
-89.8 -89.8
244.
Initial altitude 7
STOP IN LINE 210
READY
Figure 13. Program TRAJ/GD1 using run of figure 6.
We now use the capability built into TRSJ/GD1 . The trajectory of
a vehicle launched at 45 0 and having a typical drag value is shown
in figure 1 4. This run was made using an integrating interval of 1 se-
cond and took 48 seconds of machine time. However, due to the
lower launch angle and the drag, the trajectory was 40 seconds long
instead of 70 seconds as before. The running time was, therefore,
longer per second of flight time than any previous trajectory. Note
that the discrepancy between the numerical and analytical integra-
tion is significantly worse than before. A second run made with an
integrating interval of .1 second is shown in figure 15. The agree-
RUN190
Initial altitude 7500
Initial velocity 71000
Initial gamma 745
C ( D ) *S/W = 7.0013
What is the integrating interval 71
What is the print interval 75
T
H ( NI )
H( AN )
V ( NI )
V ( AN )
G ( NX ) G( AN )
X( NI )
X ( AN )
0 .
500.
500.
1000.
1000.
45.0
45.0
0.
0.
5.
3238.
3380.
750.
755.
36.8
37.0
3201 .
3262.
10.
4836.
5115.
574.
580.
24.5
25.0
5958.
6076.
15.
5473.
5883.
465.
471.
7.0
8.0
8381.
8551.
20.
5271.
5806.
-427.
-429.
-14.0 -12.6
10542.
10759.
25.
4315.
4972.
-450.
-449.
-33.5 -32.1
12494.
12752.
30.
2667.
3441.
-514.
-509.
-48.1 -46.9
14273.
14569.
35.
374.
1263.
-599.
-592.
-58.1 -57.2
15908.
16238.
40.
-2529.
-1525.
-693.
-685.
-64.9 -64.3
17421 .
17782.
Initial altitude 7
STOP IN LINE 210
READY
Figure 14. Trajectory of a vehicle launched at 45
degrees and having a typical drag value.
42 INTERFACE AGE
CIRCLE INQUIRY NO. 6
JUNE 1980
merit between numerical and analytical is much improved, however,
this run took 480 seconds. It was considered impractical to use an
interval of .01 second as was done with the run of figure 7, since the
run would have taken 1 hour and 20 minutes. Obviously, obtaining
reasonable accuracy is already taking an unreasonable amount of
time.
RUN190
Initial altitude ?500
Initial velocity 71000
Initial qamma 745
C ( D) *S/W • = 7.0013
What is the inteqratinq interval 7.1
What is the print interval 75
T
H(NI)
H( AN )
V(NI)
V ( AN )
G(NI) G ( AN )
X(NI)
X ( AN )
0.
500.
500.
1000.
1000.
45.0 45.0
0.
0.
5.
3366.
3380.
755.
755.
37.0 37.0
3256.
3262.
10.
5087.
5115.
580.
580.
25.0 25.0
6065.
6076.
15.
5842.
5883.
470.
471.
7.9 8.0
8534.
8551.
20.
5753.
5806.
-429.
-429.
-12.7 -12.6
10737.
10759.
25.
4906.
4972.
-449.
-449.
-32.2 -32.1
12727.
12752.
30.
3365.
3441.
-510.
-509.
-47.1 -46.9
14540.
14569.
35.
1175.
1263.
-593.
-592.
-57.3 -57.2
16205.
16238.
40.
-1625.
-1525.
-685.
-685.
-64.3 -64.3
17746.
17782.
Initial altitude 7
STOP
READY
BYE
IN LINE
210
Figure 15. Run of Program TRAJ/GD1 with integrat-
ing interval of .1 second.
Program TRAJ/GD2
If we make essentially the same modifications to TRAJ/GD1 as
we made to VERTRAJ1 , we come up with program TRAJ/GD2 in
analogy to VERTRAJ2. Again in the interest of economy we present
only that part of the listing below REM * * * * * * NUMERIC ******,
see figure 1 6. The remainder of the listing is identical to that shown
in figure 12.
625 REM ****** NUMERIC ******
630 X2=-C*X472*T1 \REM X2=DELTA Xdot (N.I.)
640 H2= ( -C*X4*H4-G ) *T1 \REM H2=DELTA Hdot (N.I.)
650 X4=X4+X2 \REM X4=Xdot (N.I.)
660 H4=H4+H2 \REM H4=Hdot (N.I.)
662 X6= ( X4+X5 ) / 2
664 H6= ( H4+H5 ) / 2
670 V=SQRT ( X4? 2+H4~ 2 )
672 REM YOU DON'T USE H6 AND X6 FOR V BECAUSE YOU WANT
674 REM INSTANTANEOUS V NOT AN AVERAGE OVER TIME.
680 IF H4<0 THEN V=-V
690 IF X4< >0 THEN 710
695 IF H4> 0 THEN G4=90
698 IF H4=0 THEN G4=0
700 IF H4<0 THEN G4=-90
705 GOTO 720
708 REM YOU DON'T USE H6 AND X6 FOR G4 BECAUSE YOU WANT
709 REM INSTANTANEOUS G4 NOT AN AVERAGE OVER TIME.
710 G4=ATN(H4/X4) *R9
720 X3=X6*T1 \REM X3=DELTA X (N.I.)
730 H3—H6*T1 \REM H3=DELTA H (N.I.)
740 X=X+X3
750 H=H+H3
760 IF V<0 THEN IF H<0 THEN Z=1
770 NEXT
READY
BYE
Figure 16. Program TRAJ/GD2
Sample Runs on TRAJ/GD2
We repeat the run of figure 9 as closely as we can, as a check, see
figure 1 7. Again the fractional differences are due to the slightly off
vertical launch. This run took 70 seconds compared to 63 seconds
for the run of figure 1 3. The additional time was of course due to the
added complication of the iterative procedure in program TRA-
J/GD2. The runs of figures 14 and 15 are repeated in figure 18
and 1 9. The running time for figure 1 8 was 53 seconds versus 48
for figure 1 4, and the running times of figures 1 9 and 1 5 were 1 0
times as long. The differences between the numerical and the
analytical results are about one-third as much as in figures 18 and
/
/>.:
i.
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CIRCLE INQUIRY NO. 57
INTERFACE ACE 43
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1 9 as they are in figures 1 4 and 1 5, whereas the running times only
differ by about 1 0%. Once again we see that averaging the rate data
over the integration interval yields a large improvement in accuracy
with only a small increase in running time. We observed the same
effect before in program VERTRAJ2.
Initial altitude 7500
Initial velocity 71000
Initial qamma 789.8
C ( D) *S/W = 70
*** THE ANALYTICAL EQUATIONS FOR X AND H BECOME INDETERMINATE
IF DRAG=0 . H ( AN ) AND X(AN) WILL NOT BE PRINTED. ***
What is the inteqratinq interval 71
What
is the
print interval
710
T
H(NI)
H( AN ) V ( NI )
V ( AN )
G(NI) G ( AN )
X ( NI )
0 .
500.
1000.
1000.
89.8 89.8
0 .
10.
8891.
678.
678.
89.7 89.7
35.
20.
14065.
357.
357.
89.4 89.4
70.
30.
16022.
35.
35.
84.3 84.3
105.
40.
14761.
-287.
-287.
-89.3 -89.3
140.
50.
10282.
-609.
-609.
-89.7 -89.7
175.
60.
2586.
-930.
-930.
-89.8 -89.8
209.
70.
-8327.
-1252.
-1252.
-89.8 -89.8
244.
Initial altitude 7
STOP IN LINE 210
Figure 17. Program TRAJ/GD2 repeating the run of
figure 9.
RUN190
Initial altitude 7500
Initial velocity 71000
Initial qamma 745
C ( D) *S/W = 7.0013
What is the inteqratinq interval 71
What is the print interval 75
T
h(ni)
H( AN)
V ( NI )
V ( AN )
G ( NI ) G( AN )
X( NI )
X ( AN )
0.
500.
500.
1000.
1000.
45.0
45.0
0 .
0 .
5.
3367.
3380.
750.
755.
36.8
37.0
3254.
3262.
10.
5070.
5115.
574.
580.
24.5
25.0
6051.
6076.
15.
5798.
5883.
465.
471.
7.0
8.0
8503.
8551.
20.
5676.
5806.
-427.
-429.
-14. G -12.6
10689.
10759.
25.
4793.
4972.
-450.
-449.
-33.5 -32.1
12660.
12752.
30.
3212.
3441 .
-514.
-509.
-48.1 -46.9
14455.
14569.
35.
981.
1263.
-599.
-592.
-58.1 -57.2
16103.
16238.
40.
-1861.
-1525.
-693.
-685.
-64.9 -64.3
17627.
17782.
Initial altitude 7
STOP IN LINE 210
Figure 18. Program TRAJ/GD2 repeating the run of
figure 14.
RUN190
Initial altitude 7500
Initial velocity 71000
Initial qamma 745
C(D)*S/W = 7.0013
What is the inteqratinq interval 7.1
What is the print interval 75
T
H(NI )
H( AN )
V ( NI )
V (AN )
G ( NI ) G( AN )
X( NI )
X( AN )
0 .
500.
500.
1000.
1000.
45.0
45.0
o.
0 .
5.
3379.
3380.
755.
755.
37.0
37.0
3261.
3262.
10.
5110.
5115.
580.
580.
25.0
25.0
6074.
6076.
15.
5874.
5883.
470.
471.
7.9.
8.0
8546.
8551.
20.
5794.
5806.
-429.
-429.
-12.7 -12.6
10752.
10759.
25.
4954.
4972.
-449.
-449.
-32.2 -32.1
12743.
12752.
30.
3419.
3441.
-510.
-509.
-47.1 -46.9
14558.
14569.
35.
1235.
1263.
-593.
-592.
-57.3 -57.2
16225.
16238.
40.
-1558.
-1525.
-685.
-685.
-64.3 -64.3
17766.
17782.
Initial altitude 7
STOP IN LINE 210
Figure 19. Program TRAJ/GD2 repeating the run of
figure 15.
FURTHER IMPROVEMENTS
Unfortunately, closer approaches to reality in the equations in-
crease the running time so rapidly that trajectory equations must be
numerically integrated using techniques very much more
sophisticated than those discussed herein. Reference back to figure
2 and a reminder of the simplifying assumptions included in their
derivation should convince the reader.
There are. however, many equations in engineering and the
sciences which require numerical integration and for which the
methods presented herein are quite adequate. Hopefully the reader
has gained an appreciation of the difficulties, an awareness of some
of the pitfalls, and a useful tool for the solution of some of the more
intractable differential equations.D
44 INTERFACE ACE
CIRCLE INQUIRY NO.
JUNE 1980
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CIRCLE INQUIRY NO. 59
INTERFACE ACE 45
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THE
MIN
REVOLUTION
By Merl Miller
The year is 2005. Three days ago you entered the hospital with an
operable tumor. Two hours ago you were given a mild sedative that
has made you both euphoric and sleepy. Now the time has come for
you to enter the surgical unit. As the anesthesiologist attaches your
breathing apparatus, you marvel at how comfortable the unit is, and
are pleased to hear your favorite soft music. What? Whatever hap-
pened to harsh bright lights, hard tables, a preponderance of white
and scalpels? By the 2 1 st century these things may be only memor-
ies. I predict that by the 21st century medicine will become a more
exact science, and will forever shed its “black magic” image.
Let’s look at how the operation might be performed. To start with,
the patient lies on the cushioned floor of a large transparent box. He
has a breathing and anesthetic mask on his nose and mouth. Beside
him are rows of trays carrying all instruments the surgeon might
need. Each instrument’s handle is a hollow tube. Scissors, forceps,
sewing devices. . .all have threaded ends that can easily be attached
to the surgeon’s instrument-holding rods. The primary surgical in-
strument is the laser.
Another sterilized instrument tray stands ready to replace the first
through a sterile lock. The box in which the patient lies is sterilized
between operations with steam and ultraviolet rays. The roof of the
box carries a television camera. The surgeon can move the camera
lens anywhere within the box. Back-up cameras are strategically
located throughout the box. Each camera is capable of from two-to-
ten times magnification, if needed.
The box lid has ten arms, each of which ends in a rod that can fit
any of the instruments, including the laser. The surgeon sits at a
control desk facing the television screens. The control desk is attached
to the surgical table, and all interconnecting rods run between. If the
surgeon wants, he can look over the control desk directly onto the
operating table. He inserts one of his arms into a close fitting elec-
trosensitive glove that reaches from fingertips to shoulder. These
gloves are crucial to the entire procedure so I will explain how they
work separately. First, let’s see how the surgeon uses them.
Each fingertip of the glove is connected to the computer, which is
in turn connected to the rods. The surgeon uses one hand to control
the equipment, the other hand to operate. The electrosensitive glove
emulates the surgeon’s hand movements exactly. If the surgeon
makes a sewing movement, it causes the rod attached to the needle
to sew. If the surgeon wants to make an incision, he can do so using
his index finger. All he has to do is tell the laser that it is operated by
the index finger. Then, whatever the surgeon does with his index
finger, will be duplicated by the laser.
The surgeon can manipulate his instruments with as much free-
dom and dexterity as if they were directly in his hands. But the con-
trol system gives him a steadiness of hand far greater than could
otherwise be achieved. Not only do the holders follow his finger ex-
actly, but he can feel the resistance to movement and the weight of
the tools as if he were holding them. If he wants to hold an instru-
ment in an exact position, he has only to turn it off. The instruments
can be of wide variety in size, so he can limit the size of the incision
necessary to reach difficult areas.
The main television camera can be controlled by head move-
ments so that, when the surgeon looks at something, so does the
camera. The side cameras are always on, so he can check them at
will. He can adjust the lens to give the exact picture needed.
46 INTERFACE ACE
CIRCLE INQUIRY NO. 18
JUNE 1980
A little farfetched? Not really. Some of these things are in use
now. For instance, a camera that looks where you do has been used
in military applications for some time.
Let’s now turn our attention to the most important piece of equip-
ment — the electrosensitive gloves. They will be lined with elec-
trodes and have a few microprocessors and other integrated circuits
embedded in them. These devices will be used for only one thing:
producing output that can be interpreted by the computer. Each
surgeon will have his own glove, and his own interpretation module,
“trained” to respond to signals from his arm.
Each movement of each finger will be interpreted by a group of elec-
trodes. As the electrodes sense movement, a signal will be sent to an
internal microprocessor (or glove) where a movement signal is created.
This signal is sent to the interpreter and from there to the main com-
puter for action. As computers operate in picoseconds, and humans
still operate in seconds, the system should be extremely sensitive.
This leads us to my final prediction. If you remember, last month’s
column had a short comment about direct “brain link” communica-
tion with a computer. I foresee the time when you will be able to
operate a variety of devices simply by thinking about them. Such an
application in surgery is fascinating.
Imagine a situation where a surgeon has been trained to have a
certain physical feel for operating. During his schooling he has an
opportunity to practice his skills using both computer simulation and
some of the methods in use today. He starts his internship by watch-
ing other surgeons at work and assisting in minor surgery. All minor
surgery is performed in the manner previously described. Even-
tually, he is allowed to participate in minor surgery until he exhibits a
prescribed degree of proficiency. At this point, he takes his last
series of medical exams, and is awarded a degree in surgery. He is
now allowed to perform minor surgery and diagnose problems for
referral to a master surgeon.
I foresee the time when
you will be able to operate
a variety of devices simply
by thinking about them.
Such an application in
surgery is fascinating.
At some point, he may decide to become a master surgeon.
Again, there will be a series of time and proficiency requirements to
meet, and he will have to specialize in a particular field. This last
phase of training will be the most difficult because it involves a great
deal of mental discipline. However, most people who begin the
course will probably complete it. Remember, by definition we are
dealing with a group of overly intelligent people, starting with phase
one, who find this training both exhilarating and fascinating.
It seems to me that at least some of the training involves total isola-
tion. It won’t do for the surgeon to be distracted when making an in-
cision. He must learn to concentrate precisely on what he is doing.
Let’s look in on a 21 st century master surgeon at work. He sits at
a control desk surrounded by TV screens. He wears a skullcap device
connected to the computer. He carefully looks at the main camera
console which is connected to his skullcap so it moves when he does.
The patient is bathed in pale blue light so the brighter lights of the in-
struments show each phase of the operation with great precision.
The small white penlight on the laser indicates exactly where the
beam will fall when it is turned on. He wants to check the path of the
incision so he thinks to himself, “penlight on; at my direction, hover
over the patient and follow this path. Starting here, make an incision
one centimeter deep and four centimeters long. Record this for the
laser.” Addressing the laser, he thinks, “laser, start at the specified
point, and make the recorded incision.”
This sounds terribly slow, but remember he is thinking. The en-
tire operation can be done at a modified speed of thought. It will
require an enormous amount of discipline, practice and training;
but it can be done.D
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CIRCLE INQUIRY NO. 22
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• 32K-byte image memory on the basic system
• 32, 64, 1 28 & 256K bjke system capacity
• LJghtpen input
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support software
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441 California Ave., Palo Alto, CA 94306 415/494-6088
JUNE 1980
CIRCLE INQUIRY NO. 20
INTERFACE AGE 47
ARE
Selector III C-2, produced by Micro Ap in San Ramon, CA adver-
tises heavily as an “information management system.” Promotional
literature stresses a distinction between the accounting function and
the “storing, processing and reporting of information,” and it is
these latter functions that Selector is designed to perform.
In substance, what Selector does is give the user a multi-key
“indexed” access to files which the user defines. Through this
ISAM -type of file management, the user can input, sort, extract and
manipulate data, producing custom reports to specific user needs.
As such, this puts Selector in the class of a practical “data base
management system.”
Selector runs under the CP/M operating system, using either
CBASIC or M BASIC. It needs at least 25K of memory space,
which means that with CP/M, plan on at least a 48K system. It is
designed for an 8080, 8085 or Z-80 microprocessor and two disk
drives (while it is possible to get by with one, it’s very difficult and
time-consuming). Disk formats supported include those found on
Dynabyte, North Star, Micropolis (Vector MZ), TRS-80, Cromemco
and others. The system costs about $350, including a diskette and
50-page manual.
A word of warning — Selector is not designed for the novice.
Since sophistication and power have the price of complexity, this
program should not be a first purchase. However, once a micro-
computer user has a handle on the power of CP/M and under-
stands how to use CBASIC, there should be no hesitation.
Selector is distributed in source code, which means that changes
can be made to the program before they are “compiled” and used.
This also means that revisions are easy to incorporate. Micro Ap is
one of the few distributors of software that takes the responsibility of
“updates” seriously.
Before launching into programming with Selector, the user
should spend a little time reviewing what a database is, and how
such things are usually handled on micros. Since the system comes
in source code and has tremendous flexibility, some work on the
user end will be necessary for implementation.
Selector programs are all menu driven and have the following
general divisions:
A. DEFINE — a set of programs used to create, delete, change or
modify files. Included are utilities to get files from disks, and put
them back (rather than having to use PIP).
B. SET — Selector operates under the program philosophy that a
user loads all the information into the database and then “selects”
information using the parts of the database that are needed. The
SET series allow the user to define what is to be selected and
what order they are to be selected in.
C. SELECT — Once a user has defined the commands to select data,
the Select programs use these criteria to generate a set of file
pointers — a set of directives created as the result of the programs.
These pointers are, in essence, indexing schema or an ordering
list used to place the files in logical order for the user’s application.
D. REPORT — A series of programs which produce the desired
output from the database. A command set is created determin-
ing which records shall be included, what their order shall be and
what format they shall be printed in. This order can be saved for
continued use, and everything from mailing labels to complex
reports can be generated.
E. UPDATE — A series of programs that provides the information
management. A menu allows the user to select whatever activity
is desired, including making new entries, retrieving information
(including a “dump” of the database), a sequential record recall,
changing information, deletion of records, etc.
The user can create files with predefined sorting and report criteria
for later (and continued) use, or the programs can be used to pro-
duce reports on a one-shot basis. It is possible to link other pro-
grams into the Selector input and output cycles so the user can
create production programs to enter large amounts of data.
As an extra bonus, the Selector package contains applications
programs including sales, inventory, accounts receivable and
payable, disbursements, client records, and appointments. The pur-
pose of all these ready-to-run programs is to show that the applica-
tions contained within Selector can go beyond the traditional
database concept.
The experienced programmer will have no difficulty using Selec-
tor as a “nested” utility to generate some elegant applications pro-
grams. For the programmer with a limited background, the ex-
amples and the source code are more than sufficient.
DEFINING THE DATABASE
The Selector programs used to define files are completely menu
driven. It is relatively easy to set up new files. The user is asked for
the filename, the number of fields and the program sets up a little
table that the user completes in order to define data elements. There
are six data types which are supported:
Alphanumeric Numbers to 999.999 + /-
Alphanumeric key (1st 10 characters) Numbers to 999,999.999 + /-
Numeric key (up to 999,999.999+/-) Numbers to 999,999,999.999 + /-
The most obvious question from a novice user is “why so many
types of data?” The answer is the effect upon memory requirements
and the corresponding limitations on the systems as to the number
of transactions that can be accommodated in a session.
Note that decimals of up to three places are supported — which is
more than adequate for any business application. Additionally, the
program contains edit capabilities. The nature of a data element is
“built-into” the file so that report writing is simpler. Types of editing
include:
Dates (as either mmddyy or yymmdd, displayed with hyphens,
such as 03-15-80)
Area code (nnn)
Phone number (nnn-nnnn)
Social security number (nnn-nn-nnnn)
Decimal point precision from 0 to 3
Currency ($NNNN.NN)
After the size, in terms of number of characters and data type, has
been determined by the user, Selector will compute the actual
record size and display this information. Thus the user has an oppor-
tunity to know the size of the packed records before implementing it.
The programmers at Micro Ap were apparently aware of a user’s
typical reaction to large file size. By providing the actual size and
giving the user the opportunity to change the record before it is “set
in concrete,” the program does a great service to all overly zealous
programmers.
Selector’s manual contains an ominous warning about record
sizes: “Bear in mind that if the actual record size being read or put is
not equal to the assigned record size, the program will ‘bomb.’ Files
that are open at this time will probably be corrupted. . .” This is
more a function of CBASIC than of Selector, however.
Another limitation imposed upon Selector by CBASIC is the
maximum record size. Since CBASIC limits all strings to 255 bytes,
the maximum length of a record is 255 bytes.
Previously, the function of “select and sort sets” was touched
upon. Selector uses these files to do the actual record selection and
construction of the pointer list to the selected records.
The “select set” is created in a fashion analogous to the selection
of record parameters. Again, the program is entirely menu driven,
so the operator need only answer questions as they appear. Promo-
tional literature advises that “multiple Boolean selections” can be
made. For the non-mathematician user, this has less than crystal-
clear meaning. What it encompasses, however, is a selection meth-
odology that allows any combination of the following tests to be
used to select a record:
48 INTERFACE ACE
JUNE 1980
Equal to Not equal to Less than
Between two values In a list of Greater than
Contained in a field Less than or equal to Greater than or equal to
As many as 24 criteria can be entered, and can have multiple criteria
for any field. The tests can operate as test 1 and test 2 or, alternately,
test 1 or test 2. That’s where the Boolean reference comes in.
Once a record test is constructed, it is used to create a list of those
records that pass the tests. This list, essentially an index, is called a
select set by Selector. There is room for about 1 25 record pointers
for every 1 000 bytes of free memory space. In a 48K system, this
allows about 2250 records selected from the file.
In use, the select set tests the data file sequentially, testing each field
designated as a test field against the test value according to preset
criteria. If the tests match, a pointer to that file is placed in an array.
REPORT
The report section of Selector is superior to most database
management systems. The program allows the report to be
generated in a number of sequences, including report sequence,
ascending or descending key sequence using any key field or in the
order specified by a “select set.” “Report” also has an option to
have the report include summaries, sub-summaries and even the
capability to prepare minima, maxima, averages and of course
grand totals. To top it off, the report program numbers the pages.
A common misconception concerning report generators for
database management systems is that they allow the user to con-
struct any kind of report. Of course this is fallacious, since a report is
generally limited to a list of elements of the database, with totals and
subtotals. Elaborations of the report function require custom soft-
ware to be written. With Selector it is feasible, since the user has ac-
cess to the file structures, and can list the “report” program to ex-
amine parts of it. Through thoughtful planning, the informational
reports generated by Selector should be sufficient.
One feature of CCA’s data management system missing from
Selector is the ability to define one field as a computational result of
another field. In other words, field 2 might be defined as field 1 x
1 5%. This feature is useful in some database applications; however,
with proper programming of the input programs, the necessity for
this kind of “internal computation” is largely minimized. □
^ OOQOOOOOO>OOOOOOOOQOt O OOOOmOOmOQOQOQQQ9QPOPOQmQOQQmQQMP gMQmmMMmMMMj?£
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RESIDENTIAL PROPERTY ANALYSIS
system 300.00
MAGIC WAND® Word Processor 400.00
RM COBOL® (Z80 code) 750.00
Osborne & Assoc. CBASIC source programs —
O&A Payroll w/Cost Accounting $250.00
O&A Accts. Rec./Accts. Payable . . . 250.00
O&A General Ledger w/Cash Journal . 250.00
O&A CBASIC books for above (each). . . . 20.00
Send 30C SASE for CP/M Users Group software
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® MAGIC WAND is a registered Irademark ol Small Business Appliraliuns. trx
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C IE [R (N L E (T L^lC ts (714) 848-1922
ic.
oj 8041 NEWMAN AVENUE • SUITE 208 • HUNTINGTON BEACH. CALIFORNIA 92647 e
INTERFACE AGE BACK ISSUES
1979
□ MARCH — Curing the Music Business Blues; An Income Averaging Program; Help Your Computer Keep Its Cool; M6800 Program Relocator
□ APRIL — Industrial Robots; Protype; A Low-Cost. High Quality Word Processor; High Performance. Low Cost New Printer; 6502 Memory Test Program
□ MAY — Sales Record Keeping; Two Views of Credit; The iCOM 451 1 Hard Disk System; A Simplified Method of Binary Number Subtraction
□ JUNE — The Automated Home; Computing Lumber Costs; Interfacing a Numerical Chip to the TRS-80; Home Poison Control
□ JULY — Need A System Cabinet? Build It; Saving Time While Keeping Minutes; Integrated Circuit Testing for Hobbyists; Flexing with Flex Utilities
□ AUGUST/SEPTEMBER — Handicapped Byte Back; Changing Acres to Yards to Rods. . .; Speed Up Your SWTP 6800; Make the Computer Work for You
□ OCTOBER — Personal Computers in the Classroom; A Classroom Record Keeper; Alpha Micro Review; APL for the Z-80
□ NOVEMBER — Selecting Your First Computer; The Pathology Bookkeeper; Cromemco’s System Three; The Sport of Sorting
□ DECEMBER — The Computerized Artist; Volume Projection for Small Business; A Color Television Interface; Using TRS-80 Codes
1978
□ FEBRUARY — Medical Applications
□ APRIL — Robotics
□ JULY — New Products Directory
□ AUGUST — Games
□ SEPTEMBER — Educational Applications
□ OCTOBER — Hardware Index
□ NOVEMBER — Software Index
□ DECEMBER — Book Index
1977
□ MARCH — New Products Directory
□ MAY — Floppy ROM #1
□ JUNE - Bionics
□ JULY — New Products Directory
□ AUGUST — Astronomy/Astrophysics
□ SEPTEMBER - Floppy ROM #2
□ OCTOBER — Meteorology/Environment
□ NOVEMBER — New Products Directory
1976
□ APRIL — Teleprinter Maintenance
□ OCTOBER — Basic Diet Planning
□ NOVEMBER — New Products Directory
ALL ISSUES
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JUNE 1980
INTERFACE AGE 49
By Roger Garrett
Contributing Editor
A CRIME FIGHTING SYSTEM
Before I got into the computer field, I spent about a year and a half
as an investigative assistant with the New Haven, Connecticut police
department. One of the other aides was developing a system to
assist in the apprehension of bank robbers. Essentially, she took a
map of the roads around each bank and marked off the roads most
likely to be used by a suspect when fleeing from the scene of the
crime. She then identified those intersections where the positioning
of police officers or roadblocks would probably be most effective in
capturing the suspect.
The system was effective as far as it went; but it had many faults.
Any change in street status (such as changing from one-way to two-
way or road construction obstructing passage) rendered her maps
obsolete. Whenever a bank opened a new branch, someone had to
draw up a new map. Her set of maps only handled bank robberies; if
someone decided to hold up a jewelry store, the maps were useless.
What was really needed was a real-time interactive computer-based
suspect apprehension system.
Let’s assume we have a computer with a large database system
and a color graphics terminal with light pen and keyboard. The data-
base includes two forms of information. The first form comprises a
graphic representation of the city streets that can be displayed and
moved around on the color monitor. The other form is a set of data
describing those streets; traffic direction (one-way, two-way, dead
end), street linkages (how they intersect), traffic flow (approximate
speed based upon time of day, day of week, and season of the year),
and traffic control (where stop signs, traffic signals, etc. are and how
they operate).
The light pen and keyboard allow the dispatcher to enter data into
the system, which responds by producing appropriate displays. He
can, for example, indicate to the system that a crime has occurred at
some point in the city, (any point, not just at banks) and the system
will display that area of the city. With special color codes being dis-
played in real-time, the computer assists the dispatcher in deploying
police personnel to apprehend the suspects. (See figures 1 through
5.) With such a system, the computer no longer remains just a tool
but becomes a partner, actually helping the operator with intelligent
suggestions.
FIGURE ONE
The dispatcher receives a call that a crime has occurred at a
jewelry store on the corner of Third Avenue and Fifth Street and that
the suspects were seen leaving the scene of the crime in a north-
bound vehicle. The dispatcher picks up his light pen and touches
the reset button followed by the vehicle north and crime location but-
tons. If he can visually locate the appropriate position on the dis-
played map, he touches his pen to that point. Otherwise he types in
the crime location on his keyboard. The system responds by dis-
playing a red square at the location on the map.
FIGURE TWO
The system plots the possible routes that the suspects may take.
The yellow area indicates the areas that could have been reached
had the suspects been running rather than riding in a car. The green
sections indicate where a vehicle could have traveled in the elapsed
time. The blue area indicates a 1 -minute projection into the future
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CRIME LOCATION: Third Ave & Fifth St
INTERCEPTION POINTS:
FRIDAY JAN 6 80
8:56:03 A.M.
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CRIME LOCATION: Third Ave & Fifth St
INTERCEPTION POINTS: Fifth Ave & Seventh St
Sixth Ave & Second St
Seventh Ave & Fifth St
FRIDAY JAN 6 80
8:57:42 A.M.
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Figure 2.
50 INTERFACE ACE
JUNE 1980
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CRIME LOCATION: Third Ave & Fifth St
INTERCEPTION POINTS: Eighth Ave & Sixth St Car 6
Eighth Ave & Fourth St Officer 15
Sixth Ave & Second St "
FRIDAY JAN 6 80
8:59:34 A.M.
LOCATION LOCAT.ON VEHICLE 0N FOOT *°° DELETE HENofb
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Figure 3.
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CRIME LOCATION: Third Ave & Fifth St: Apprehended
INTERCEPTION POINTS:
FRIDAY JAN 6 80
9:06:48 A.M.
N
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location | LO cati 0 h | location | L oc°fiON VEHICLE ° N °°
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CRIME LOCATION: Third Ave & Fifth St
INTERCEPTION POINTS: Third Ave & First St
Elm St & Oak Dr Car 12
Eighth Ave & First St
FRIDAY JAN 6 80
9:02:17 A.M.
N
W — | E
CRIME
LOCATION
PATROL
CAR
LOCATION
OFFICER
LOCATION
ROAD
BLOCK
LOCATION
VEHICLE
ON FOOT
ADO
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APPRE
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Figure 4.
where the suspects’ vehicle could travel. In determining the green
and blue areas, the computer takes into account that the vehicle was
traveling north along Fifth Street when last seen, that certain roads
are one-way streets, and also the approximate traffic flow rates for the
time of day, day of week, and season of the year.
The system has also displayed several yellow-centered green
squares as potential interception points and has noted their locations
at the bottom of the screen. These represent intersections which the
computer has determined would be best for positioning police per-
sonnel in order to apprehend the suspects.
FIGURE THREE
A few more moments have passed and the system continues to
update the display. The recently displayed green -centered red
squares indicate positions of police personnel who have called in
and reported their positions, which the dispatcher then enters as data
either via the keyboard or the light pen. As the computer updates the
suggested interception points, it can now take into consideration the
estimated amount of time necessary for an officer to get to that loca-
tion. It also displays the police car or officer which it suggests be sent
to the interception points. The dispatcher can accept the sugges-
tions and appropriately deploy the personnel or make his own deci-
sions. Of course, as a given police department gains confidence in
the system, it might allow the system itself to do the dispatching via
voice synthesis over the police radio.
FIGURE FOUR
Several officers are dispatched and arrive at crucial intersections,
effectively blocking escape routes. If the computer has access to the
city’s traffic light system, it might even halt traffic in some areas in order
to slow down or stop the suspects. Note that there is relatively little
blue on the map now, indicating a good chance of apprehension.
FIGURE FIVE
Finally, after dispatching car 1 2 towards the corner of Elm and Oak,
the officer reports that the suspects have been apprehended, indicated
by a clearing from the display of all symbols except the crime loca-
tion, apprehension symbol, and police personnel symbols. When
the dispatcher touches his light pen to the reset button, the symbols
disappear and the system is ready for the next incident. □
JUNE 1980
INTERFACE AGE 51
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driver. 50-pin I/O connector for S-100
expansion. 25-pin parallel interface;
25-pin serial interface. Serial interface
operates one or two cassette recorders.
Graphic resolution of 240x512, 30
lines of 64 characters, 8x8-dot matrix.
Character generator contains full ASC II
set (upper & lower case), plus standard
graphic symbols. User may define up
to 128 characters. Keyboard is 63-key
data processing type, plus 16-key
numeric pad.
□ Video Display: industrial grade
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□ Display Disk: single unit package
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□ S-100 Expansion Unit: self-
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Software
□ Development PAC™
□ Word Processing PAC™
□ EPROM PAC™
□ Microsoft Disk-Extended BASIC
□ CP/M™ Operating System
'U S. domestic prices only Subject to change without notice
CP/M is a Registered Trademark of Digital Research
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CIRCLE INQUIRY NO. 29
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CIRCLE INQUIRY NO. 26
MAKE VOUR BASIC
BETTER FOR BUSINESS
Developing business applications without keyed file support is like
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Enter MAGSAM "
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Supporting Cast
MAGSAM’s advanced features and capabilities include:
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The versatile MAGSAM file management is now available in two
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CALL FOR ARTICLES
INTERFACE AGE is seeking
articles on hardware and software in
the areas of medical and educational applica-
tion, special functions of microprocessors, telecom-
munications and video graphics, both screen and hardcopy.
The payment rate for articles ranges from $20 to $50 per pub-
lished page. Pieces describing company projects or products will
carry the company byline, but no payment is offered. Submittals
should include an abstract, outline and stamped return envelope.
Manuscripts should be typed, double spaced with one-inch
margins. Minimum length is four pages, unless programs are in-
cluded. Photos should be numbered and have a brief description
attached. Tables, listings, etc. should be on separate pages.
Computer listings should be printed using a new ribbon to assure
good reproduction. Authors are requested to submit a statement
of their background and expertise.
The publisher assumes no responsibility for artwork, photos or
manuscripts. No acknowledgement is made unless accompanied
with a stamped return envelope.
L For article submission or more information, write Editor,
^INTERFACE AGE Magazine, 16704 Marquardt Avenue,
Cerritos, CA 90701 . Please do not phone.
EfW
54 INTERFACE AGE
CIRCLE INQUIRY NO. 46
JUNE 1980
MEASUREMENT SYSTEMS
ANOjCQNTROlS INC
MODEL DMB 6400
•TTLDM-250
■ . . -v -_> r r
MEASUREMENT
systems S. controls
incorporated
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JUNE 1980
INTERFACE AGE 55
Teach Your PET to Read
“M arked Cards!!
By Marvin Mallon
“Marked cards’’ herein do not refer to the kind that may net
you a fortune in Las Vegas. They refer to those ubiquitous
IBM -style cards that are designed for alphanumerical data entry
tasks. More specifically, the mark sense cards that are read by
any device sensitive to the presence of a pencil mark. This is
not to be confused with the more familiar punched cards.
For many decades, the mark sense card has been used in
conjunction with mini and maxi computers for the recording
of inventory, survey results and school examinations (see
figure 1 ). It has proven to be a simple and reliable means of
entering great quantities of pre-recorded data into a com-
puter in a fast and efficient manner. With the recent introduc-
tion of the inexpensive MR500 Mark Reader manufactured
by Chatsworth Data (photo), the mark sense card is now a
viable consideration for the micro. Prior to the production of
this small $750 unit, similar devices normally sold for many
thousands of dollars and overshadowed the microcomputer
both in price and size.
A key to the reasonable selling price lies in the manner in
which this system “senses” or “reads” the cards. Older
models used optical scanning techniques with costly elec-
tronics. This unit scans the width of the card as it passes
through the reader with a series of 1 3 sets of metal brushes.
When a pencil mark (preferably #2 or softer) comes under a
brush set, the conductivity of the graphite is sufficient to pro-
vide a pulse from that channel. Twelve of the channels fall in
line with the conventional spacing of a Hollerith encoded
IBM card. The remaining channel (to the far left) is reserved
for the sensing of pre-printed conductive timing marks which
are a necessary clue as to which row is being read.
Another cost-cutting measure incorporated in the MR500
is the absence of a hopper or bulky collector box for the
cards. This small, lightweight unit (4 pounds, inches
cubed) is intended for a one-at-a-time card reading. Opera-
tion is simple. The card (suitably pencil marked) is pushed
NAME
COURSE
10 ® 0
'0 . HI 0
0 0 0
0 0 0
0 0 0
0 0 0
000000
000000
000000
000000
000000
ANSWERS
0 0
0 0
0 0
0 0
0 0
0 0
0 0
10 0 0
0 0 0
0 0 0
0 0 0
0 0‘0
0 0 0
0 0 F
If "
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
— nr|
Figure 1. Special card used in the Test Scoring pro-
gram. Note conductive timing marks along left edge.
56 INTERFACE AGE
JUNE 1980
into the slit-like opening at the front of the unit. A switch
senses this action and a motor starts the rollers which pull the
card through. It emerges directly out the back in less than a
second and the motor shuts off. The card can be as long as
you wish to make it. I have designed cards that are 1 1 inches
in length, printed on both sides and requiring two passes
through the reader. It all depends on the application.
The units are available with interfacing for the TRS-80,
Apple II and the PET. Suitable hookup instructions and soft-
ware routines are furnished. My work specifically had to do
with using the reader as a peripheral for the Commodore
PET. One application involved a test scoring program which
I will now explain in some detail. A complete listing of the
program is shown in Listing 1 .
This program was created by Dr. Sam Spero of Cleveland
and has been translated for use with the Apple II as well as
the PET. It opens with a message explaining that each
student’s marked card will be scored and that other factual
class comparisons will be derived and displayed. The graphic
symbols (lines 14, 45, etc.) are PET’s unique control sym-
bols for clearing the screen and positioning the cursor. The
user is then asked to set the parameters of “number of pupils
tested’’ and “number of questions on the test.” An option is
then provided whereby the instructor can input responses
relevant to missed questions. This provides some guidance
to pupils who use this program and are in need of corrective
study information.
The program then asks for and accepts the key card. This
is the prepared master marked with the right answers. After
that, the pupils’ cards are inserted, read, scored, and
displayed. When all of the students’ cards have been thus
entered, a display of the summary of all test scores is shown.
This provides an overview of class performance. The mean
test score is calculated and shown along with the standard
deviation figure for the class as a whole. A bar graph
(histogram) is also presented which portrays very graphically
how the class scoring was distributed.
At this point, if the option has been taken, individual grade re-
ports are displayed along with the previously entered commen-
taries relevant to each missed question. All in all, the program
cleverly provides a fast and efficient means for test scoring and
student feedback. The concept is readily adaptable to a broad
range of educational and business requirements.
An elaboration on the subroutine which I created for card
reading and scoring by the PET will now be discussed. Note
that the card illustrated in figure 1 has the answers arranged
two to a row. I will later cover the method that can be used to
differentiate the answer in the left-hand half of the card from
the right-hand side. It is essential to provide various state-
ments and subroutines within the BASIC program which will
provide the overall result of reading each row of each card
passed through the Mark Reader. It is also desirable to check
for such errors as misread timing marks. The values derived
for each row read must then generally be decoded into rele-
vant information for the program’s usage.
MACHINE LANGUAGE ROUTINE
Due to the speed with which a card passes through the
reader, it is not feasible to have a BASIC routine accomplish
the reading and error-checking. It is best to employ a
machine language routine which executes rapidly when called
by PET’s SYS command. Such a routine must be POKE’d
away into memory prior to calling it for the first time. The
subroutine starting at line 1 0000 is complete and has the
POKE routine (line 1 0005) as well as the converted 6502
operation codes.
When the program is run, 1 66 bytes of memory starting at
location CA (whatever you wish that to be) are altered to con-
tain this card reading routine. One of the best locations for
this storage is in the normally unused second cassette buffer
starting at address 826. Address 634 (tape buffer #1) can
also be used providing you neither read nor write to the
cassette during the program’s execution. In general terms,
this routine reads as many rows as have been previously
identified in variable CC%(0). It checks to make certain that
the count agrees with the number of timing marks seen by
the Mark Reader. If not, then the value of ST (status) is
altered and a means is thereby provided for the program to
recognize and act on this condition.
The routine further accomplishes the task of passing the
cumulative decimal value of the binary representation of
each row to an array labelled CC%(X). When this routine has
been executed and the return to BASIC is made, the values
pencilled on the card may then be found in this array.
“OLD” PET MODIFICATION
Certain addresses in the previously noted routines are
unique to the new PET (1 6K and 32K large keyboard). They
must be changed if this routine is to be used in an old PET.
The 33 changes to be made are accomplished with the sub-
routine starting at line 4C000.
INITIALIZATION
To make use of the machine language routine it is first
necessary to set some values in the program. In the state-
ment at line 1 0 we have:
1 . cleared the PET of all variable values.
2. established the number of rows (or lines) on the scor-
ing card as 55 (or whatever is relevant for your pur-
poses). This is the same as the number of in-line tim-
ing marks that are pre-printed in conductive ink on
the card.
3. dimensioned an array of that size.
4. set the lowest element in that array to that same value.
IMPLEMENTING LANGUAGE ROUTINE
Line 90 sets the starting address for the machine language
routine storage location. In this case, it is the first cassette
buffer. Then the subroutine previously described is called
and executed. Line 95 calls for the “old” PET modification
routine but only if a PEEK at location 50000 reveals that the
program is running in an old PET. This statement takes ad-
vantage of an idiosyncrasy of the earlier PETs that prevent
you from examining the BASIC ROMs.
CARD INPUT MESSAGE
The three statements starting at line 215 inform the user
that they are to place a card through the Mark Reader. Line
225 tests for an error and loops back to the beginning after
an appropriate message.
CARD INPUT SUBROUTINE
The simple subroutine starting at line 30000 resets the
special array (CC%), waits until you have inserted a card,
executes the machine language routine, and signals an
“OK” if the card was read correctly.
DECODING
For the split row scoring cards, the routine starting at line
6200 translates a pencil mark into the appropriate answer.
Lines 6240 to 6300 change a pencil mark on the left hand
half of the card into either an A, B, C, D, E or “-” (indicating
no answer). Lines 6340 to 6400 do the same for the right
half. In line 6230, J represents the actual number of answers
to be calculated which may be less than or equal to NL. The
X loop starts at 6 rather than 1 because the first 5 rows (in
this example) are reserved for the student’s ID number.
These routines, for the most part, can be transplanted into
other application programs. With a little imagination, the
combination of the Commodore PET and the new Chats-
worth Data MR500 Mark Reader should prove useful in
many ways.D
Program follows
JUNE 1980
INTERFACE AGE 57
58 INTERFACE AGE JUNE 1980
PROGRAM LISTING
20 PRINT"
22 PRINT"
23 PRINT"
25 PRINT"
27 PRINT" 3.
28 PRINT"
29 PRINT" 4.
30 PRINT"
31 PRINT"
32 PRINT"
33 PRINT"
34 PRINT"
35 PRINT"
37 PRINT"
39 PRINT"
41 PRINT"
42 PRINT"
1 .
2 .
5.
7.
1 REM TEST SCORING PROGRAM
2 REM RE-WRITTEN FOR THE **PET**
3 REM BY COMPU-GUOTE <21 3 >348-3662
4 REM FOR CHATSWORTH DATA
5 REM LAST REVISION 7/30/79
6 REM VERSION 2. 1
10 CLR : NL=55 : D I MCCX < NL > CCX<0>=NL
14 PR I NT "73"
15 PR I NT "THIS STTEST SCORING" PROGRAM WILL"
16 PRINT
SCORE EACH STUDENT'S TEST."
PRINT STUDENT'S NAME, # OF CORRECT"
AND WRONG ANSWERS, TEST PERCENT,"
AND A LIST OF PROBLEMS MISSED."
PRINT A FREQUENCY TABLE OF TEST"
SCORES. "
COMPUTE THE MEAN TEST SCORE AND THE"
STANDARD DEVIATION."
PRINT AN ITEM ANALYSIS OF EACH TEST"
QUESTION. "
PRINT A BAR GRAPH OF TEST SCORE"
DISTRIBUTION. "
PRINT EACH STUDENT A NOTE GIVING:"
A> STUDENT'S SCORE"
B> # OF QUESTIONS MISSED"
C> A BRIEF REMARK ABOUT EACH WRONG"
PROBLEM"
45 GOSUB500 PRINT " WlWW"
60 PR I NT "HOW MANY PUPILS WERE TESTED?
61 PRINT":«UWW"
62 PR I NT " HOW MANY QUESTIONS ON THE TEST? " ; : GOSUB20000 : J=VAL< VV* > = PRINT"73"
63 IFJ>100THENPRINT : PRINT" 3100 QUESTIONS IS THE MAXIMUM" : PRINT : GOT062
68 DIMSN$<P>,BS<J>
69 DIMWP<P> , TS< J+2> , W< J>
70 DIMW1H<P,J>
90 CA=634 : GOSUB 10000
95 I FPEEK < 50000 > =0THENGOSUB40000
104 PR I NT "WOW"
106 PR I NT "DO YOU WISH TO INPUT RESPONSES TO MISSED";
107 PR I NT "QUEST IONS ?"
108 PR I NT : PRINT : PR I NT " 3PRESS V OR N ";
1 09 GETQ$: : I FQ$= " " THEN 1 09
110 I F Q$= " N " THEN 145
111 PRINT"73" PRINT PRINT
112 PRINT" TYPE IN THE RESPONSE YOU WISH THE"
114 PRINT" COMPUTER TO MAKE TO WRONG ANSWERS."
115 PRINT: PR I NT "TYPE A S< RETURN >■ WHEN YOU HAVE FINISHED."
116 PRINT : PRINTTAB<9> "DO NOT USE ANY COMMAS."
117 PRINT : PRINTTAB<9> "TYPE 'N' IF NO COMMENT."
119 PRINT PRINT" EXAMPLE ": PRINT
120 PR I NT "YOU HEED TO STUDY THE MATERIAL ON PAGE"
121 PR I NT "57. LOOK AT PROBLEM #5 CAREFULLY."
124 GOSUB500
125 FORS-l TOJ
: GOSUB2000O : P= VAL < VV* > : PR I NT " 73"
128 PR I NT "73" PRINT PRINT PRINT PRINT
129 PR I NT "RESPONSE TO QUESTION #";S
132 PRINT
133 PRINT"?"; GOSUB20000B*<S>=VV*
135 IFB*<S>=" N"THENB*<S>=" NO COMMENT."
140 NEXTS
145 PR I NT "73"
150 PRINT" SINPUT KEY CARD",
1 55 GOSUB30000 PRINT: GOSUB6200
160 IFR*O n "THEN 145
170 ANS=L*
200 F0RXS=1T0P
210 PRINT"73";
215 PR I NT "SINPUT STUDENT CARD",
220 GOSUB30000
225 I FST>0THENPR I NT PR I NT " SFLEASE RE-ENTER THE SAME CARD" : G0T0215
228 PR I NT : PR I NT " STUDENT ID-";
230 GOSUB6000 : SN* < XS > =L$
232 GOSUB6200
234 IFR*<>" "THEN210
259 PR I NT "73"
260 FORS=lTOJ
270 IFMID$<L$,S, 1>=MID$<AN$,S, 1>THEN290
280 W<S>=W<S>+1 WP<XS>=WP<XS>+1 = W1HCXS, WP<XS> >=S
290 NEXTS
300 C**J-WP<XS> : TS<C>*TS<C> + 1
320 NEXTXS
340 GOSUB990 • GOTO 1010
400 PR I NT " : FORX= 1 T023 : PR I NT : NEXTX : PR I NT " SDEF'RESS ANY KEY FOR NEXT PAGE"
405 GETR$ : IFR$=" "THEN405
410 PR I NT "73" RETURN
500 PR I NT " fl" : FORXT= 1 T02 1 : PR I NT : NEXT
510 PR I NT " SPRESS < RETURN)"
520 GETA* : I FA*= " " THEN520
530 PR I NT " 73" : RETURN
990 PR I NT " 3STUDENT " TAB < 23 > " SI TEMS "
1000 PRINT " m RIGHT";
1001 PR I NTTAB < 8 > " sWRONGS 3AVG. "TAB <23> " 3*11 SSED"
1005 RETURN
1010 FORS=lTOP
1020 C=J-WP<S> : AV=INT<C*100/J+.5> =T=0
1030 PRINTSN*<S>
1040 PRINT" "CTAB<8>WP<S>TAB<14>AV"X";
1045 PRINTTABC19);
1050 FORN=lTOWP<S>
1055 IFW1X<S,N>=0THEN1090
1060 PRINTW1X<S,N>; :T=T+1
1070 I FT <5THEN 1 090
1071 T =0
1080 PRINT PRINTTAB< 19);
1090 NEXTN
1 092 GOSUB400 : GOSUB990
1110 NEXTS
1112 PR I NT "73"
1115 GOSUB500 : GOSUB 1120: GOTO 1 25W
1120 PRINT: PR TNT "ITEM ANALYSIS" = PRINT = PRINT
Now! North Star
Application Software!
North Star now offers application
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North Word —
NorthWord is a simple-to-operate
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for use with the popular North Star
HORIZON. NorthWord enables you
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NorthWord incorporates the most
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printing, and much more. NorthWord
can be integrated with other North
Star software packages to produce
customized letters, labels and
reports quickly and efficiently.
MailManager —
MailManager enables you to com-
pile and maintain complete organ-
ized mailing lists. Lists are easily
accessible and can be compiled
with a great deal of flexibility. Entries,
corrections and deletions are easily
made. The North Star MailManager
can print your list on individual enve-
lopes, on mailing labels, or in com-
pact summary form.
InfoManager —
InfoManager is a powerful list-
oriented, data management system.
It will accept up to 50 categories of
information for each record and has
the ability to select and sort before
printing. The North Star InfoManager
has power and flexibility for many
applications: product inquiry, in-
ventory, customer/client records,
calendar reminders, and as an easy
way to fill in often-used forms.
GeneralLedger —
General Ledger and Financial
Reporting, two programs in one,
maintains general ledger accounts
based on such input as checks,
bank deposits and journal entries,
and uses the information in the
general ledger to produce custom-
ized financial statements and
financial reports.
NorthWord is the central building
block for all the North Star applica-
tion software to follow. Packages
now being tested include other
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CIRCLE INQUIRY NO. 50 V V
NoithStar
North Star Computers, Inc.
1440 Fourth Street
Berkeley, CA 94710
(415) 527-6950
TWX/Telex 910-366-7001
60 INTERFACE ACE JUNE 1 980
|
1240 PRINT" SITEM #"TRB<7)"SW CORRECT "TRB< 18) " 3W WRONG " T RB < 27 > " STi CORRECT"
1 245 PRINT: Q=0 RETURN
1250 FORS=lTOJ
1260 C=P-W<S> :RV=INT<C*100/P+.5)
1270 PRINT" "STAB<12>CTAB<20>W<S>TAB<27)flV"X"
1275 G=Q+1 : IFQO15THEN1280
1 276 GOSUB400 : GOSUB 1 1 20
1280 NEXTS
1290 PRINT GOSUB500
1300 PRINTTAB<9)"»=;UMMflRV OF TEST SCORES" = PRINT
1310 PRINT" STTEST SCORE"," M OF TESTS"
1315 PRINT Q=0
1320 FORS*JTO0STEP-1
1330 I FTS < S > =0THEN 1 350
1340 PR I NTT RB < 4 > ST RB < 23 ) TS < S )
1350 NEXTS
1355 GOSUB500
1356 SU=0 : M=0
1360 FORS=lTOJ : M=M+TS<S)*S : NEXTS
1370 M=MXP
1 380 FORS=1TOP • D=< J-WP<S> >-M : SQ=D*D : SU=SU+SQ • NEXTS
1390 SD=SQR < SU/P )
1400 PRINT " : PR I NT : PR I NT : PR I NT : PR I NT : PR I NT : PR I NT
1420 PR I NT "THE MERN TEST SCORg IS"M= PRINT
1430 PR I NT "THE STRNDRRH DEV I RT I ON IS"SB
1440 PRINT :GOSUB508
1500 PRINT"58" PRINT: PRINT PRINT: PRINT
1550 PRINT" SffiRR GRRPH OF TEST SCORES" : PRINT : PRINT
1552 M=0 : XB= 1
1555 IFJ>13THENXB=J/13
1556 R=INT<XB> : IFA<XBTHENXB=INT<XB)+1
1560 FORS=0TOJ
1570 I FTS < S > >MTHENM=TS < S >
1580 NEXTS
1590 PRINTSTR$<M>;
1600 FORS=JTO0STEP-1
1610 I FTS < S > <MTHEN 1 630
1620 fl=3*<J-S)
1624 R= I NT < < RXXB ) +2 )
1625 I FS-XB< 1 0THENR=R- 1
1628 PRINTTRB<fl> "*" ;
1630 NEXT
1 650 PR I NT : M=M- 1 : I FM< 1 THEN 1 680
1660 GOTO 1590
1680 PRINT
1685 FORS=JTO0STEP-XB
1689 IFS<10THEN1 694
1690 PRINTSTR*<S>;
1692 GOTO 1760
1694 PRINT" "STR*<S>;
1700 NEXT
1710 PRINT GOSUB500
1800 IFQ$="N"THEN1 864
1801 V-l
1802 FORS-1TOP
1803 ONVGOTOl 804, 1807
1804 PRINT"*" F0RX9-1T011 = PRINT : NEXTX9 : PR INTTRB< 14> " SGRfiDE REPORTS"
1 805 PR I NTTflB < 1 4 > " ************* " • GOSUB500 : PR I NT " a"
1 806 PR I NT : PR I NT = PR I NT : PR I NT : GOTO 1811
1807 PRINT"*" : F0RX9=1 TG21 : PRINT • NEXTX9
1808 PRINT" 3PRESS < RETURN) FOR NEXT STUDENT REPORT.";
1 809 GETfl* : I FA*= " " THEN 1 809
1810 PRINT" 73" PRINT PRINT: PRINT: PRINT
1811 PRINTTRBC5) "STUDENT # "SN*<P>", PRESS < RETURN)"
1812 PRINTTRB<5> "TO DISPLRV VD UR TEST RESULTS."
1813 GETR* I FA$= " " THEN 1813
1814 PR I NT "73".: V=2
1815 RV=INT < <J-WP<S> >*100/J+. 5)
1820 IFWP<S)=0THEN1870
1825 PR I NT "STUDENT # "SN*<S) H VOUR TEST SCORE IS"RV"X"
1830 PRINT
1835 PRINT"RND VOU MISSED THE FOLLOWING QUESTION/S : " ;
1836 PRINT PRINT
1840 FORX=lTOWP<S) :PRINTW1X<S,X); " ** * '• NEXT
1842 PRINT T=0: 0=4
1844 F0RX=1T0WP<S)
1846 PRINT PRINT"QUESTION #"W1Z<S,X>
1850 N*W1X<S,X> :PRINTB*<N)
1858 T-T+l : I FT =OTHEN 1 865
1860 NEXTX
1861 PRINT " *" : FORTX= 1 T02 1 : PR I NT : NEXTTX
1862 NEXTS
1864 END
1865 T=0 : IFX=WP CS)THEN1 860
1 866 PR I NT " : FORTX- 1 T02 1 : PR I NT : NEXTTX
1867 PRINT" I'M RFRRID THERE'S MORE PR I NT "PRESS < RETURN)"
1868 GETA$ : IFR$=" "THEN1868
1 869 PR I NT " 73" : 0=5 ■' GOTO 1 860
1 878 PR I NT : PR I NT : PR I NTTRB < 1 3 > " SCONGRRTULRT I ONS " : PR I NT
1875 PR I NT "VOU MRDE R 100X ON THE TEST. ": GOTO 1861
6000 REM GET STUDENT ID
6005 L*=""
6010 FORD= 1 T05
6030 Z2=CCX<D)
6040 Z1=Z2X2Z2=0
6050 I FZ 1 >2THENZ l=Zl/2 : Z2=Z2+ 1 : GOTO6050
6060 L*=L$+RIGHT$<STR*<Z2), 1)
6070 NEXTD
6080 PR I NTL$ : RETURN
6200 REM CRERTE RN ANSWER STRING
6210 L$=""
6230 F0RX=6T0J/2+5.5
6235 C*="*"
6240 N=CCX < X ) RND62
6250 I FN=0THENC*= " - "
6260 IFN=2THENC*="A"
6270 IFN=4THENC*="B"
6280 I FN=8THENC*= " C "
6290 I FN= 1 6THENC$= " D"
6300 IFN=32THENC$="E"
6310 L*=L*+C*
6320 C*="*"
JUNE 1 980 CIRCLE inquiry no. 21 INTERFACE AGE 6 /
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6340 N=CCX < X > RND3968
6350 I FN=0THENC® : = " — "
6360 I FN= 1 28THENC$= " fl "
6370 IFN=256THENC$="B"
6380 I FN=5 1 2THENC$ : = " C "
6390 IFN=1024THENC$= M D n
6400 I FN=2048THENC$ : = " E "
6410 L*=L*+Ct
6415 NEXTX
6420 FORD=0TOJSTEP5
6430 F0RY=1 T05
6440 D$=" "
6450 I FD+V= J+ 1 THEN6530
6460 I FD-*-V< 1 0THEND$= ” "
6470 I FD+V>9flNDD+Y< 1 00THEND^= r ' "
6480 PRINTD*.;
6490 PRINTD+Y;MID$:<L*,D-»-V, 1>; N
6500 NEXTV : PR I NT NEXTD
6530 PR I NT " «•’ : F0RX- 1 T022 : PR I NT : NEXTX
6532 PRINT" SIDEPRESS SPACE BAR TO CONTINUE. DEPRESS "
6534 PR I NT " 3 ,ANV OTHER KEY TO RE-ENTER LAST CARD, "j
6536 GETR$ : IFR$=" "THEN6536
6540 RETURN
10000 REM READ A CARD
1 0005 FORX=0TO 1 65 : READY : POKECfl+X , Y : NEXT : RETURN
10010 DATA120.216, 160,0, 169, 195,209,44
10015 DATA208, 5, 200, 209, 44, 240, 7, 169,64, 141, 150,0
10020 DAT ASS, 96, 160, 6, 177, 44, 200, 2G0, 209
10030 DATA44, 16,7, 169,32, 141, 150,0,88,96, 133
10040 DATA 165, 198, 165, 177,44, 133,164, 169,204, 141
10050 DATA76, 232, 200, 162,0, 134, 160, 134, 161, 169
10060 DATA16, 44, 18,232,240,84,44,79,232, 16
10070 DATA79, 112,242, 173,79,232, 162,236, 142,76
10080 DATA232, 73, 63, 5, 161, 133, 161, 173,79,232
10090 DATA 162, 204, 1 42, 76, 232, 73, 63, 5, 160, 133
10100 DATA160, 44, 79, 232, 16, 44, 80, 221 , 165, 160
10110 DATA10, 10,70, 161,106,70, 161, 106, 170, 165
10120 DATA161 , 41 , 15, 145,44,200, 138, 145,44,200
10130 DATA 198, 164,48, 16, 198, 165, 16,7, 169
10140 DATA16, 141, 150,0,88,96,44,79,232,48, 159
10150 DATA 169, 0, 141 , 150,0, 165, 164,240,5, 169, 1, 141, 150,0,88,96
20000 REM INPUT ROUTINE
200 10 V=1 : V*= “ " : W*» " "
20020 GETV* : I FV*= " " THEN20020
20030 PR I NTV$ ; : I FV*=CHR$ < 20 > THENV=V- 1 : W$=LEFT$ < W* , V > = V^= " " : GOTO20020
20040 V-V+l :W*«VV<=+V*
20050 IFV*OCHR*<13>THEN20020
20060 IFW$=" " +CHR^ < 1 3 > THEN200 1 0
20070 W$=LEFT$ < VV* , V- 1 > RETURN
30000 REM CARD INPUT ROUTINE
300 1 0 F0RZ= 1 T0NL CCX C Z > =0 : NEXTZ
30020 NA I T5947 1,128: SYS CARD
30030 I FST=0THENPR INT" 5J0. K. "
30040 RETURN
40000 REM CHANGE TO OLD PET
40010 F0RX=1T033 : READY, Z : P0KECA+V, Z : NEXT
40015 RETURN
40020 DATA7, 126, 12, 126, 18, 12, 19,2,25, 126
40030 DATA29, 126,35, 12,36,2,40,53,42,53
40040 DATA44, 126, 46, 52, 56, 43, 58, 49, 84, 43
40050 DATA86, 49, 98, 48, 100,48, 109,48, 113,49
40060 DATA1 16, 49, 120,49, 124, 126, 128, 126
40070 DATA131 , 52, 135,53, 141,12, 142,2
40080 DATA153, 12, 154,2, 156,52, 162, 12, 163,2
63000 REM PROGRAM END
READY.
S ystem of the Month
The Escon Selectric Interface
By Hampton G. Miller and Andrew Klossner
An IBM Selectric typewriter can serve as an output device
for almost any computer when interfaced via Escon’s Selec-
tric Converter Model E-A. This product includes a factory
assembled universal adapter, together with a modification kit
which enables the mechanical operation of the typewriter to
be controlled by a program. The kit is easily installed in a few
hours; no drilling or other permanent modification is made
to the Selectric. The adapter can be any one of a number of
standard output devices, eliminating the need for special
hardware or software.
The Selectric has established a solid reputation in the field
of office typewriters. With the classic golf ball typehead
replacing the usual typewriter keybars, a wide variety of type
fonts and special character sets are available. At slightly over
ten characters per second, a Selectric cannot match speed
with the faster daisywheel or dot matrix printers, but it is an
excellent output device.
The universal interface consists of a small box of elec-
tronics, including a 6502 microprocessor, which accepts
ASCII characters from the computer and translates them into
mechanical movement of the elements within the Selectric.
Options for connecting the universal interface to a computer
include TTL, 20 ma, and RS232 serial interface, with three
handshake protocols and sixteen baud rates; TTL parallel
with three handshake methods and selectable polarity; and
two IEEE-488-1975 modes. An interface unit which plugs
directly into an S-1 00 bus is also available. The interface is a
separate unit from either the Selectric or computer; it is con-
nected by cable to both, and draws power from the typewriter.
The first modification step is to cut and strip the electro-
magnet wires. Then three rods controlling shift interlock,
switch interlock, and return interlock are removed from the
typewriter to make room for the electromagnet assemblies.
Next the “select” and “function” electromagnet assemblies
are installed, and the three interlock rods are replaced. The
“case shift” electromagnet assembly is installed; then all
electromagnet wires are spliced into the cable to the interface
unit, and the cable is tied to the frame. Now an ohmmeter
test is conducted. When it passes, the unit is ready for power
and can be tested by the interface unit.
To connect the interface to the computer, the interface and
handshake methods must first be chosen. Handshaking occurs
when the interface buffer becomes full or when it later empties.
When the buffer becomes full, the interface signals the com-
puter that it must stop sending characters; as the buffer empties,
it signals the computer that more characters may be sent.
These signals may be in the form of logic lines which change
62 INTERFACE AGE
JUNE 1980
There are two
sides to our story.
Side One
The DISCUS “2+2 Quad -Density Hardware
factory mounted in a cabinet with
power supply, fully-buffered S-100
single-board controller, and inter-
connecting cables. All fully
assembled, system-tested and
fully warranteed.
You get the speed and
efficiency of 1.2 megabyte-
per-diskette memory. . .
and you get it for 0.13$
per byte.
Now you can use your
S-100 system to tackle big
jobs. Because the DISCUS™
2+2 Quad-Density Disk
System puts 1 .2 megabytes of
fast-access memory on your
side for just $1545.00 complete.
With the DISCUS™ 2+2 System
complete means complete.
You get a full-size (IBM-
compatible 8") double-sided/
double-density disk drive,
Side Two
The DISCUS2+2 Quad -Density Software
1.2 megabyte quad-density hard-
ware is only one side of the story.
The DISCUS™ 2+2 System price
includes all the fully-interfaced,
high-performance software you
need to take full advantage of your
quad capacity.
The system includes our exclusive
BASIC-V™ virtual disk BASIC, which
allows you to address your quad-
density diskettes as easily as main memory. The
operating system you get is the widely accepted
CP/M* 2.1 . And you get our powerful DISK-ATE
text editor/assembler; The most advanced software
development tool available.
Micro-Soft BASIC 5.1 and Micro-
Soft FORTRAN are available as
options. Both run under CP/M* 2.1.
Check out the full system price of
DISCUS™ 2+2 Quad against any
other floppy disk system at your
local computer store. At $1545.00,
we think you'll take sides with
DISCUS™ 2+2.
If your dealer doesn’t carry THINKER TOYS
products, write MORROW DESIGNS Inc., 5221
Central, Richmond, CA 94804. Or call (415)524-2101
9-5 weekdays (Pacific Time).
MORROW DESIGNS 7 Thinker Toys
*CP/M is a trademark of Digital Research.
JUNE 1980
CIRCLE INQUIRY NO. 67
INTERFACE ACE 63
CT 102 -A CLOCK/ CALENDAR
SI 00 Dus
FEATURES
• Time of doy in hours, minures G seconds
• 24 hour rime formor
• Month G doy dote function
• Crystal controlled rime base
• Fosr b slow set functions allow rapid setting of rime G dare
• Ourpur is torched BCD
• Simple read instructions allow simple interface to
BASIC, CPM, ere
• Will run with 4 MHz processors The T102-A rin
• Optional battery backup capability used for ony c
• Low battery drain in bock-up mode 5-1 5 MA Time & dote. /
depending on volroge method allow
• Con be located or any group of 4 I/O language to t
port addressed Outputs ore la
• Basic E software example provided the digit then
• SI CXD bus signals used PWR. SOUT. 5INP FastserGslow:
• Easy interface to ony SI 00 bus fast rime G do
processor
The T102-A rime dote board can be
used for any application requiring
Time G dote. A simple to use reading
method allows the simplest BASIC
language to be used
Outputs are latched BCD. just select
the digit then read it.
Fast set G stow set functions provide for
fast rime G dote setting.
Optional bortery backup capability. A simple to construct charging circuit is included in the
manual. Any 8 to 18V unregulated DC source is all that is required for backup.
The T 1 02 comes assembled and tested. Each board includes an easy to use manual with
basic software programs for setting and reading rime and dare
Price $149.95
COMPU/TIME P.O. BOX 5343
HUNTINGTON BEACH. CA. 92646
(714) 536 5000
CIRCLE INQUIRY NO. 15
New 248-page book includes all the former TIS workbooks
except “PET Graphics.” Provides information for both ROMs and
a comprehensive index. Only $14.95.
Also from TIS
WB-3 PET Graphics $4.95
Software products on cassette or floppy disk with complete instruction
manual. Each $24.95 (cassette), $29.95 (diskette).
SW-1 MAIL B mailing list system
SW-2 CHECKBOOK record
SW-3 ACCOUNTS keep track of who owes you how much
SW-4 MEDIT create and maintain date files
SW-5 CALENDAR appointments, meetings at-a-glance
TIS
P.O. Box 921, Dept. IA Add $2 ($5 foreign orders)
Los Alamos, NM 87544 shipping and handling
PET and CBM are trademarks of Commodore Business Machines
state when the signal is being sent (hardware handshaking),
or characters which are sent to the computer (software hand-
shaking). Most peripheral interfaces use one of these
methods, so there should be little work involved in configur-
ing the computer hardware or software for Selectric operation.
PERSONAL EXPERIENCE
One of the authors used the Escon system to interface a
vintage Selectric to a Heath H1 1 (LSI-1 1 based) computer.
Modifying the typewriter and connecting the interface took
less than eight hours. A TTL level parallel interface (which
previously ran a paper tape reader/ punch) was used, and the
standard paper tape punch software properly drove the terminal.
SELECTRIC OPERATION
When a Selectric is manually operated, a key is pressed
and a character is typed. As the key is depressed, code bails
are coaxed into position and engage latches to select one of
four possible tilts and eleven possible angles of the typeball.
The shift key reverses the typeball, giving eleven new angles,
for a total of 88 possible characters. After the latches are set,
the power cam is actuated, causing the typeball to tilt, rotate,
and strike the paper through the ribbon. The typeball carrier
then advances one column to the right and is ready for the
next character. The non-printing controls include the shift,
carrier return, index (line-feed), space, and tab keys.
Under control of the Escon interface, the code bails are
directly manipulated and the print cycle is initiated using
electromagnets. The return and space functions are also per-
formed in this manner. Another electromagnet assembly
controls the shift operation. The microprocessor handles the
exact timing requirements for carrier return, shift, and
between-character delays, and overlaps shifting with spacing
when possible. It contains a 51 1 character buffer to allow for
surges of output; handshaking suspends computer output
when the buffer needs time to empty.
As well as standard ASCII (including upper and lower
case), the interface responds to special codes which can sus-
pend output to allow manual typing or typeball changing,
sound an optional alarm, stop typing and clear the internal
buffer, and continually print the contents of the buffer. The
interface methods and self test off-line pattern generation are
controlled by DIP switches in the interface unit.
INSTALLATION
To assist in the modification of the Selectric, the unit in-
cludes a 37-page assembly manual, a 23-page book of illus-
trations, and a 28-page reference manual. Escon will per-
form the modification for labor and shipping costs, promis-
ing to complete within two weeks.
CAVEATS
A few cautions regarding the system’s limitations are in
order. Unlike the IBM 2741 computer terminal based on the
Selectric design, the Escon/Selectric unit does output only.
Pressing keys will cause typing to occur, but will not transmit
any information back to the computer. Thus, the system is a
printer, not an interactive terminal.
The system does not perform the tab, backspace, or
return-without-index operations. This reduces its usefulness
for word processing where backspace is required for
underlining.
Experience suggests that a Selectric without an impression
control would not be as easily converted as the later models.
Finally, if a Selectric is turned off while it is typing, it may
become damaged.
CONCLUSIONS
The Escon system is easy to install, interfaces to almost any
computer, and provides reliable, professional looking hard
copy at a low cost. It is an excellent investment for a personal
computer hobbyist or a business person with a small system. □
64 INTERFACE AGE
JUNE 1980
A little dull around the edges?
Routine? Predictable? Boring? Maybe
all it needs is a little Interlude. Interlude is
the most stimulating computer game ever conceived
It combines a computer interview, an innovative
programming concept, and a one-of-a-kind manual to
turn your love life into exciting, adventurous, delicious fun!
CIRCLE INQUIRY NO. 39
ow’s your
love life?
Interlude is: romantic . . . playful . . . outrageous ... a fantasy. Interlude is: ■ Wet fun
on a hot summer night. (Interlude #21) ■ A surprise on the way home from dinner. (Interlude #42)
■ A bubble bath that ends with a bang. (Interlude #78) ■ An evening to rest while she does all the
“work.” (Interlude #25) ■ The most romantic of evenings. (Interlude #84) ■ A new twist to an
old subject. (Interlude #69) ■ Just watching her. . . (Interlude #57) ■ An erotic fantasy! (Interlude #33)
With over 100 Interludes, you can satisfy all levels of interest and desire. Each Interlude is fully
described in the manual, and the more elaborate ones are detailed with regard to settings, props, and
mood-enhancing techniques. But we’ve saved a few super Interludes for that very special time when your
interview indicates you’re ready! At that time, you will be introduced
to one of several Interludes held secret within the computer. (When you
learn secret Interlude #99, your love life may never be the same again!)
Interlude can give you experiences you’ll never forget. Are you ready for it? The Ultimate Experience.
Interlude
Interlude, 10428 Westpark, Houston, Texas 77042 I’m really ready! Rush me
□ For the Apple II (16K) # □ For the TRS-80 (Level II-16K) ## □ $14.95 for cassette
.copies of Interlude today.
□ $17.95 for diskette.
Add $1.50 for shipping. Texas residents add 6% sales tax. My check (payable to Interlude) is enclosed. □
"Charge my □ MASTERCHARGE □ VISA account.
Account No. _ . .
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Signature
Namp
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State
Zip
"CHARGE CUSTOMERS: Order by phone toll-free! 1-800-327-9009 Ext. 306
# Apple II is a registered trademark of Apple Computers, Inc. # # TRS-80 is a registe red trade mark of Rad io Shack , a T andy Co.
The Dust Writer
By Michael J. Hodgetts
University of Tennessee
At the University of Tennessee Rehabilitation Engineering
Center in Memphis, we work with severely handicapped
children to find ways to get around the effects of their handi-
caps. Alaine Marty is a little girl who has cerebral palsy which
prevents her from using her legs, arms and vocal organs.
She communicated with her teachers by eye movements,
looking left for yes and right for no. But a faster way to com-
municate that would not require an extra person’s coopera-
tion was needed. The Electronics Department was asked to
adapt a new electronic device, called a TIC, which was devel-
oped at Tufts-New England University Medical Center.
With this device, a switch is closed once to select one of
several rows of characters. The scanner then stops in that
row, and the user hits the switch a second time to select a
character from the row. The character is then displayed on a
small CRT.
We were asked to replace the switch with a photo-cell that
could be operated by a head mounted light-stick (a special
#.*•
type of flashlight). Since it is hard to look at a letter and then
move to point the light at it, the final solution was a head-
mounted mercury switch. But in the process of her trying the
aiming method it became obvious that she could aim the
light very accurately.
An idea formed. Why not wear a head mounted light pen
and use a screen two feet away as a keyboard? For low power
and portability the screen was constructed from sixty-four
LEDs and the light pen was designed to respond to the fast
rise time of the light from the pulsed LEDs. This new device
permits her to communicate much faster than ever before
and she may compose messages or school work on an out-
put device without anyone else helping. She calls the unit
Aunt Martha.
Aunt Martha uses a CRT terminal for output and is not
portable. For the system to be portable, a lightweight device
is needed. It must also draw very little power, be readable in
daylight and must be low in cost. For this purpose it should
display at least three or four lines of thirty-two or more char-
acters. In the interest of safety, voltages should be kept below
thirty volts. The device should have the potential for graphics
display as well as upper and lower case characters.
Let’s look at the technology available. *
1 . Cathode-Ray Tube Terminal
Too much power consumption, weight and size. Also
a CRT uses high voltages, and washes out in daylight.
2. Neon
Again too much power consumption, high voltage and
daylight washout.
3. Vacuum Fluorescent
Power consumption is lower in small displays but day-
light washout is still a problem and large displays are
not readily available.
4. Light Emitting Diode
Power consumption is too high and daylight viewing is
not good. Also the cost for a large display is excessive.
5. Liquid Crystal Display
Someday this may be the answer but for now the cost,
availability, and driver complexity mak£ it impractical.
To give the system some mobility, we designed a device
that is lightweight and draws very little power. It can be
mounted on the front of a wheelchair with little trouble.
The Dust Writer draws no power except when actually
writing a new character. It is lightweight, small, inexpensive,
and may be viewed in bright light.
The principle of operation is the same as that of the Etch-
A-Sketch® toy made by Ohio Art. We actually used the
powder from an Etch-A-Sketch toy in our device. The con-
figuration is that of a drum plotter with the stylus on the in-
side of a glass drum. A stepping motor drives the stylus
horizontally with a threaded shaft. Another stepper drives a
cam for vertical motion and a solenoid lifts the stylus from the
glass when necessary. Line feed is accomplished with a small
D.C. gearmotor that turns the drum. The powder in the bot-
tom of the drum erases the old printing so that fresh media is
always fed up to the drawing field.
Many mechanical arrangements are possible and we plan
to try some others to increase the speed of the device. The
present system is fast enough for our purpose but a dot
matrix print head would make the device useful in applica-
tions requiring greater speed.
The electronic drive circuit is extremely simple and uses
only nine packages. Software controls every move of the
device through seven bits of an eight-bit output port and two
bits of an input port. The input bits are used only to initialize
the vertical and horizontal positions. The print head starts at
the left and bottom positions as determined by a sensing
switch and LED — photo transistor device respectively. After
initialization the position of the stylus is maintained in the
microcomputer.
The device will be used with a C-MOS 1 802 micro when
the system is finished. An 8080 based system is being used
for testing until the cross assembler is finished which will
make the 1 802 more convenient to use.
CONCLUSION
The system will eventually control a powered wheelchair,
making mobility and communications available through
microcomputer technology. □
Program on Page 140
68 INTERFACE ACE
JUNE 1980
Gmaphics.
The Paper Tiger puts mare Me into
erorything you do.
The Paper Tiger strikes again. With a DotPlot™ graphics
option that lets you make the most of your Apple II J TRS 80*
or other personal computer.
With DotPlot and available software drivers,
you can print screen graphics, draw illustrations,
write block letters, plot charts. And DotPlot
includes an expanded, 2K-byte buffer.
That's not all. Every Paper Tiger gives you 8
software-selectable character sizes. 80 and
132 column formats. Multi-part business forms
handling. Forms control. Reliable stepper-
motor paper drive. Adjustable width tractor feed.
Continuous duty cycle operation. Plus lots more.
t Apple II is a trademark of Apple Computer Inc.
jTRS-80 is a trademark of Radio Shack, a division of Tandy Corp.
The Paper Tiger costs only $995. The DotPlot option only
$99 more. But don’t let these low prices fool you. Because the
Paper Tiger is rugged enough to stand up to the
. most demanding printer-plotter requirements.
; mm For the name of the Paper Tiger dealer nearest
you, call toll-free 1-800-343-6412 (except Massa-
chusetts, Alaska, and Hawaii).
JB Integral Data Systems, 14 Tech Circle,
Natick, MA 01760. (617) 237-7610.
CIRCLE INQUIRY NO. 36
Integral Data Systems, Inc
Looking at Micro-Based
Business Systems
By Tom Fox,
Systems Ecfife
When we started to research late last fall, it seemed easy
enough: write an article comparing all of the available micro-
computer systems. Even living in the computer industry, we
were unprepared for the huge number of machines that ex-
ist, and the complexity contained within each one. Under-
standing how even one computer works, and unearthing its
weak and strong points, is a week’s work. Doing it for 30 or
more systems, while trying to find some common ground for
comparison among them, gave us cause for thanks that we
only do this once a year. It made us appreciate some of the
headaches the ultimate purchaser must endure in selecting a
computer system.
PICKY, PICKY
A question you may fairly ask is: How did we arrive at the
particular choice of computer systems represented here? In
large part, we selected them the same way you might: look-
ing at magazine advertisements, poking around in computer
stores, even answering a radio commercial. In researching
this subject, we visited over 20 computer stores in half a
dozen cities in three states. We wanted to see what systems
were actually available to a retail purchaser. We limited our
consideration to those systems that survived multiple
traumas of conception, development, production and distri-
bution to reach the retail level.
We realize that in demanding such stiff qualifications, we
would be limiting ourselves to machines from last year’s
state-of-the-art; it takes at least that much time for a new
product to fight its way through derelopment, production
and distribution. Because of this, we have included two or
three of the most promising new computer systems that offer
something special in the way they work or are being marketed.
Large or small, sophisticated or simple, we tried to pick a
representative sample of available equipment. It was clearly
impossible to include them all.
We are emphasizing microcomputer systems intended for
use in small business situations. Where there was a choice,
we picked a system that utilized a hard disk drive as its
primary storage medium. Although we’ve seen a lot of
powerful floppy disk-based small business systems, we think
that a hard disk drive in the ten-megabyte or larger size is
more suitable to the bulk of serious business computing.
CATEGORICALLY SPEAKING
The systems can be categorized in many different ways:
number of bits handled at once by the microprocessor (eight
or 16), bus compatibility (S-100, SS-50, etc.), capacity or
type of disk (floppy or hard), single- or multiple-terminal,
BASIC- or Pascal-based, types of application software sup-
plied and, of course, price.
Let’s begin with computers utilizing eight-bit microproces-
sors, followed by the generally higher-performance and
more expensive 1 6-bit units. We can further break down the
eight-bitters into the actual design of microprocessor utilized,
since there is a certain amount of software compatibility
within the groups, and only a limited amount of program
interchangeability outside of each family.
70 INTERFACE AGE
JUNE 1980
By far the most popular microprocessor used in small
business computer systems is the 8080 and its derivatives,
rhe 8085 and Z80. The latter two operate at a faster rate than
grandfather 8080, and the Z80 sports an enhanced instruc-
tion set at the machine-language level. There is a great deal
of already-written software that will run on all three. The sec-
ond group of eight-bit systems we will look at are those based
on Motorola’s 6800 microprocessor chip. Actually, both of
our entries this month use the advanced 6809 version.
Finally, we will look at a pair of 6502-based systems. In the
industry, this microprocessor design has been somewhat of a
sleeper, and would probably be largely unknown if the Apple
personal computer had not been such a spectacular success
in the marketplace.
Sixteen-bit microcomputers share far less commonality than
their eight-bit siblings; systems in this category tend to be more
distinguishable from each other. We have two 8086-based
designs, one that is a near copy of Digital Equipment Cor-
poration’s LSI-1 1 , and three others that are as different from
each other as they are from the rest of the entrants.
8080 GROUP OF EIGHT-BIT MICROCOMPUTERS
Altos Sun-Series
Decipher the model number for this product, and you
have a thumbnail description of the computer itself. The
ACS8000-6/MU4 is an Altos Computer Systems’ series
8000 with six serial input/output ports and a multi-user disk
operating system configured for four simultaneous users. To
keep all of these terminals satisfied, a generous 208 kilo-
bytes (KB) of Random Access Memory (RAM) is fitted inside
a tabletop enclosure that also houses the Central Processing
Unit (CPU) and dual eight-inch, single-sided, double density
floppy disk drives. It takes a separate box to hold the single-
platter Winchester-technology hard disk drive and its 14.5
megabytes of data. If more storage is needed, a dual-platter
unit can be substituted, and a second single- or dual-platter
unit can be added at the same time or later.
The multi-user disk operating system is Altos’ own AMEX,
which will run CP/M™ compatible programs and lan-
guages. Included in the price of AMEX is a hardware floating-
point arithmetic board that considerably speeds up mathe-
matical computations. Other than a rather complete selec-
tion of programming languages and programmer tools,
Altos has chosen to leave the fitting of applications programs
to their dealers and end-user customers.
Cromemco System 3
In the November 1979 issue of INTERFACE AGE, we
published an in-depth description of the System 3. Since
then, Cromemco began shipping these computers with
double-density floppy disk drives, without increasing the
price for doubling the standard storage capacity to over a
megabyte. Cromemco is one of the few survivors of the
vicious decimation of S-100 board constructors. They owe
their current strength to careful attention to product quality,
documentation and innovation in new designs.
The ten-megabyte HDD hard disk add-on is the sealed-media
type, so the floppy disk drives have to be retained to extract
backup copies of programs and data from the hard disk.
Cromemco offers more variations of BASIC (five at last
count) than any one programmer will ever use. All of
Cromemco’s software, including a unique structured FOR-
TRAN language called RATFOR, is created by an in-house
programming staff. If Cromemco is strong in systems soft-
ware, they are far from being a power in applications pro-
grams. Their two releases so far — a small Data Base Man-
agement System (DBMS) and two successive versions of a
Word Processor — have been greeted with only lukewarm
enthusiasm by users. In common with nearly every other
computer discussed this month, the retail dealers are only
too happy to fill this gap with a wide variety of stock and
custom programs that will run on the System 3.
Heath H89
The WH89 is the lightweight of this roundup, both in
terms of price and probable utility in a business environment.
It is limited to 48 kilobytes of memory and a single mini-
floppy diskette drive, although we understand that Heath in-
tends to add a dual 8” floppy disk option later this year. The
WH89, with its dual Z80 processors, is certainly fat in the
CPU department. The WH89 is actually a WH19 “smart”
CRT terminal with a single-board CPU and 5 !4” floppy disk
drive tucked into the unused corners.
Accessories include three different printers, including an
attractively-priced $795 dot matrix device. Software is
limited to a disk operating system with Benton Harbor
BASIC or the option of the more capable Microsoft BASIC
(an additional $100). The operating system is a “must buy”
option that will add $ 1 00 to the list price.
Heath’s new word processing program is so new we
haven’t seen it running as yet. It lists for $495, but you can
take advantage of a $300 discount if it’s delivered with the
new daisywheel character printer. This latter device is a re-
labeled Diablo 1640RO shown in their latest catalog at
$2895. Remember when you could buy a Heathkit hi-fi
amplifier for $79?
The Heath Co.’s new owner, Zenith Data Systems, has big
plans for the WH89-CS. Zenith is well along in its plan to
market an identical Z89 throughout the world via established
computer stores and franchises. Their goal is to have Z89s
displayed at 40% of the computer retail outlets in the United
States within six months.
Industrial Micro Systems Series 8000
An article in the December 1979 INTERFACE AGE de-
scribed the Series 8000 as a solid, middle-of-the-road repre-
sentative of the 8080 group. Industrial Micro Systems is a
hardware manufacturer, and their expertise has made the
Series 8000 a robust and reliable computer. The manufac-
turer depends on outside specialists for software, with a
choice of four separate operating systems. CP/M is the most
often asked for, and many CP/M-compatible applications
have made a cozy home in Series 8000s.
The Series 8000 comes in an Industrial Micro Systems
desk-style work station with the best maintenance access-
ability we’ve seen. (The manufacturer has made cooling fans
standard equipment subsequent to our carping about the
lack thereof.) Software is available to take advantage of the
extended memory capabilities that have always been a part of
the Series 8000 — up to a quarter megabyte in multi-terminal
systems. A new 64-kilobyte dynamic memory board is avail-
able, breaking a long-time Industrial Micro Systems tradition
of building only static RAM cards.
You can now add up to two Control Data 90-megabyte
Phoenix cartridge disk drives to a Series 8000. A Phoenix-only
system (no floppies) lists for a reasonable $ 1 0,000 or so.
Intertec SuperBrain
The SuperBrain is a new breed of desktop computer that
appears at first glance to be merely a CRT display terminal.
Two double-density 5 !4” minifloppy disk drives are barely
noticeable next to the display screen, but give up little in
capacity: nearly 700 kilobytes if you opt for the QD double-
track option. Some 40% of SuperBrain purchasers do just
that, feeling the $1,000 premium well spent. If that isn’t
enough, an 18-megabyte Winchester disk drive is available
as an add-on for $4695.
The SuperBrain is a single-board computer, meaning that it
does not have the traditional mother board with plug-in slots
for the CPU, RAM, etc. It does, however, have space inside
for a single S-1 00-compatible board. This is often occupied
by the hard disk controller, but you can add anything you like
from the large collection of available products, so long as
you curb your desire to a single board at any one time.
JUNE 1980
INTERFACE ACE 71
The SuperBrain is happiest with CP/M-style programs,
and a wide selection of languages and programming aids is
available from Intertec which fits that mold. APL should be
out in another month. This represents an ambitious under-
taking, because it requires an expanded character set for
both the keyboard and display screen. Since Intertec controls
the production of every part of the computer’s terminal, it
has the flexibility to add on such an enhancement.
Micro V MICROSTAR
Micro V is an ambitious, two-year-old California company
whose corporate roster reads like a veritable Who’s Who of
movers-and-shakers of this frantic industry. It has taken a
careful look at the marketplace (even operating its own retail
computer store for a time to get in touch with buyers’ re-
quirements) and created the MICROSTAR small business
system. It’s an 8085-based single-board computer that is
normally equipped with a dual floppy disk drive and attractive
desk-type enclosure. In common with other computer sys-
tems which intend a serious assault on the business market,
a hard disk option is available to increase data storage capac-
ity to some 20 megabytes. Micro V allows its dealers to set
end-user prices, giving them the freedom to add local soft-
ware services into the price. But you can expect to pay
around $10,000 for an average MICROSTAR system.
The MICROSTAR’s strong suit is its software. Its devel-
opers have taken the more traditional minicomputer-style
approach of serving up a package of powerful programming
tools integrated into the system. STARDOS, the multi-user
disk operating system, includes an extended business
BASIC interpreter with optimized file handling talents. Both
sequential and random (direct) files are supported, and tools
for Indexed Sequential Access Method (ISAM) are standard
on the MICROSTAR. The system features one of the most
capable DBMS-type programs (actually more of a stand-
alone language) that we have seen on a micro. UPDATE, as
it is called, allows data base entry and inquiry with English
language commands. It comes standard, too.
Micro V engineers have taken to calling the MICROSTAR
the MICROSTAR I in anticipation of the soon-to-be-
announced MICROSTAR II, an enhanced machine based on
the 16-bit 8086 microprocessor chip.
MicroDaSys millie
The national computer magazines have been running ads
inviting the reader to become an instant computer dealer by
purchasing just one “millie” (at a discount price), adding any
programs the reader can write or buy, and reselling the
resulting system at any price he chooses. Some 6,000 per-
sons responded to a month of ads, so the idea must strike a
responsive note in hobbyist souls. Actually, this business
practice describes what systems houses — and more lately
computer stores — have been doing for longer than micro-
processors have been around. MicroDaSys is presenting
anyone with the moxie to try it, a factory-supported way to
crash into the business on a shoestring. It’s a unique method
for increasing sales.
The millie itself is a repackaged System-Z, a Z80-based
dual floppy disk drive S-100 computer that emphasizes its
word processing talents to the extent that the only printer in
the catalog is a typewriter-quality NEC Spinwriter. The CRT
terminal is a new MicroDaSys design optimized to run either
the popular Electric Pencil or ascending WordStar word pro-
cessing programs. MicroDaSys’ only contribution to its fat
applications software catalog is the Pencil Sharpener and
Star Brightener. These are similar packages that enhance the
basic word processing programs to allow the merging of
mailing lists with text files to create computer generated
“personalized” form letters. Think of millie each time you
empty your stuffed mailbox in this election year.
North Star Horizon
North Star, four years old now, is an old timer in the world
of S-100, Z80-based computer systems. In that time, it has
shipped an incredible 10,000 computers and systems. To
many, the Horizon is “the one in the wood box.” In truth,
there is little else to distinguish it from many of the current
crop of microcomputer systems. These words are not intended
to slight North Star. After all, just where did all these “me
too” computers get their best ideas?
The HRZ-2-64K-D was selected by North Star as its most
popular configuration. It includes 64 kilobytes of RAM, dual
double-density 5 14” floppy disk drives with a total capacity of
360 kilobytes of data storage, a Soroc CRT terminal, and
Anadex dot matrix impact printer. For an extra $1920 you
can substitute the excellent NEC Spinwriter thimble-type
character printer. A new 1 8-megabyte Winchester hard disk
drive has recently been made available. If applications run to
large data files with floppy disk storage, opt for the quadruple-
capacity minifloppy drives and fit an extra pair for a total
capacity of nearly 1 .5 megabytes.
North Star DOS enjoys a popularity which challenges that
of CP/M as a microcomputer operating system. Almost any
computer store with a collection of software features many
useful programs that were designed specifically to run on the
Horizon. North Star itself does not offer any end-user appli-
cations programs yet, but look for developments in this line.
Pertec PCC2000
Pertec is the giant computer peripherals manufacturer that
acquired Altair soon after the latter company unleashed the
world’s first really popular microcomputer. The PCC 2000
is its direct descendent, and the most successful to date. It
features a thoughtfully integrated all-in-one package that
shows evidence of careful planning in the keyboard. The
microprocessor is the 8085, which runs 50% faster than the
8080s which graced Altair’s earlier products.
Pertec controls distribution as tightly as it does manufac-
turing. Only factory-controlled stores can sell the product,
and never with competing brands. It needn’t be so con-
cerned. When compared with the current crop of widely-
available small business computer systems, the PCC 2000
holds its own.
Radio Shack TRS-80 Model II
Here’s the monster in the lineup, if only because of the for-
midable distribution network of over 7,000 retail outlets. We
know a computer accessories manufacturer who received a
multi-million dollar order — the biggest in that company’s
history — to place just one floor sample of his product in
each Radio Shack store. This tremendous base of retail
outlets was solely responsible for making a mediocre product
— the original TRS-80 — - the most widely produced com-
puter in history. Well in excess of 1 00,000 have been shipped.
The follow-up Model II is being marketed far more conser-
vatively in only 1 50 Radio Shack computer centers and
select stores. However, not a single one of the other 6,850
outlets will turn down an order.
The Model II utilizes the same eight-bit Z80 microproces-
sor chip as the Model I, but it’s stoked up a bit more in the
younger product — 4 megaHertz as opposed to a lacka-
daisical 1 .78 megaHertz. The Model II comes with a single
8” floppy diskette drive as standard, and we recommend that
you fill up the RAM space to a full 64 kilobytes right away.
None of the Radio Shack-supplied applications programs will
run in the smaller 32-kilobyte version. The disk drive is the
72 INTERFACE AGE
JUNE 1980
PROGRAM EPROMS
WITH YOUR APPLE
NEW FROM
MOUNTAIN HARDWARE
ROMWRITER
TM
Available through dealers worldwide
Mountain Hardware, Inc.
LEADERSHIP IN COMPUTER PERIPHERALS
300 Harvey West Bivd., Santa Cruz, CA 95060
(408) 429-8600
• Fast Firmware? Send me all the details on RomWriter.
Name .
Address _
City
Phone
. State.
FASTER THAN A SPEEDING DISK!
Firmware in ROM is as fast as your software in RAM, but in
ROM it frees up RAM memory space for companion pro-
grams. And, there never needs to be a LOAD from disk!
Create firmware for your Apple* by programming
EPROMs with RomWriter.
FIRMWARE NOT SOFTWARE.
Many frequently used programs really ought
to be installed as firmware. ROM-based
firmware permits a “power up and go”
configuration. Use RomWriter to create
firmware for peripherals such as
printers or create program cards.
By installing EPROMs that you
have programmed on Mount-
ain Hardware’s ROM-
PLUS-*-™ board, program
cards of up to 12K in
length may be cre-
ated.
FEATURES.
Programs 2716 EPROMs (5V). All 2K
or part of the EPROM can be pro-
grammed. Installs in a peripheral slot.
EPROMs mount in a zero insertion force
socket. A switch turns power off to the socket
so EPROMs can be inserted or removed with-
out powering-down your computer. A Write
Protect switch is provided for programmed
EPROMs while running. A $CFFF OFF switch to
suppress this command during programming or RUNning.
EPROMs can be RUN on RomWriter, or ROMPLUS+™ when
creating firmware systems.
SOFTWARE
Virtually foolproof programming. Specify a Start and End address
in the EPROM and either a Disk File name or a starting address in
memory. Desired code will be BURNed followed by a VERIFY. Addi-
tionally, existing EPROM code can be merged with desired changes
to facilitate EPROM debugging. Easy data entry and high reliability
are designed into RomWriter. Programmed EPROMs can be RUN
while residing on RomWriter or can be transferred to Mountain
Hardware’s ROMPLUS+ board .requires Applesoft firmware.
THE RIGHT PRICE.
See for yourself how firmware can enhance the power of your Apple
system. Drop by your local computer store for a demonstration.
RomWriter and Mountain Hardware’s full line of computer products
are available at dealers worldwide.
*Apple is a trademark of Apple Computer, Inc.
CIRCLE INQUIRY NO. 49
dual-density variety, giving nearly half a megabyte of storage
capacity. Radio Shack should be commended for including a
little-publicized fact in their catalog: 15% of the first disk’s
capacity is required to hold system -related programs, and is
not available for data applications program storage. On some
systems we know, this figure runs closer to 80%.
Additional disk drives are housed in a separate cabinet that
can be optionally installed in the pedestal of an integrated
systems desk. A good selection of printers is available, in-
cluding a brand new daisywheel character printer for word
processing applications. The word processing program itself
will come along in a few months.
The new Level III BASIC is an enhanced version of the
Model I’s Level II language (just keeping the rows of Roman
numerals straight requires a computer). A generous reper-
tory of 1 1 4 different BASIC and TRSDOS commands are at
your fingertips with Level III, Model II. As for applications
programs, only the general ledger, inventory control and
mailing list are fully released. Accounts receivable has been
recalled by the factory, and payroll was being released at
press time.
TEI 3400
TEI is a Houston, Texas maker of transformers and sheet
metal products which earned an early reputation for making
the best S-100 “box” in the industry. The manufacturer filled
those boxes with computer cards and other parts, and it
came to pass that a complete machine appeared under the
TEI banner: the 3400 Business Computer System.
In talking with the factory, we get the impression that it
hasn’t firmly decided what direction its product should take.
Early advertising featured 50-megabyte Calcomp disk drives
and a snazzy two-piece CRT display terminal — both re-
placed by other products before the first systems rolled off
the assembly line. In the software area, the initially-promised
proprietary multiprocessing operating system and compre-
hensive business information management system have
been replaced with the considerably toned-down statement
that the product is CP/M compatible.
Plans are to offer a proprietary 1 50 character-per-second
printer, as well as several languages (BASIC, FORTRAN,
COBOL), in addition to making up the lost time in the busi-
ness software development project. It could happen. The
company still makes the best S- 1 00 boxes around.
Vector Graphic MZ
People always confuse Vector Graphic with North Star,
even though the two companies are separated by most of
California. Both started the same year with S-100 board
products (CPUs, memories, interface boards, etc.), and soon
integrated them into their own boxes with a pair of vertically-
mounted minifloppy disk drives on the right-hand side. Both
companies have been very successful, and recently reported
shipping some 10,000 computers out the door in the past
four years. The similarities go further, but stop abruptly when
one begins to look at Vector Graphic’s System B.
This is the model MZ Z80 microcomputer system en-
hanced with a terminal of its own design and a disk operating
system (CP/M) complete with Level V Microsoft BASIC.
The CRT display terminal goes by the humble name of
“mindless,” which says that it does not have the smarts to
decipher a character and display it on the screen in the usual
fashion. Instead, the terminal depends on a separate S-100
board (supplied with the System B) mounted in the com-
puter chassis. One advantage is that the terminal runs in the
memory mapped mode, and can reflect display changes far
more rapidly than even the fastest of ordinary “dumb” or
“smart” terminals.
Software includes a screen-oriented text editor for pro-
grammers; an even more advanced word processor is avail-
able for the business user. The well known Peachtree family
of business programs (general ledger, accounts payable,
accounts receivable, payroll and inventory control) comes
standard at the quoted price, but you must pay extra for the
printer required to utilize them.
Zilog MCZ-1/70
Here’s an interesting story. Zilog — the supplier to the
world of the ubiquitous Z80 microprocessor — has decided
to come out with its own computer system and compete
directly with its own best customers. The idea is not all that
new, but it has never been carried off successfully. Years of
effort in marketing industrial minicomputer systems has
hardly made Texas Instruments a power in that field, and Na-
tional Semiconductor recently cried “uncle” in its attempt to
sell business computers. Both of these companies are giants
in the semiconductor industry. Why have they failed to make
a mark by putting their chips together into a stand-alone sys-
tem? It’s a fascinating question, but too long to go into here.
Today’s news is that Zilog is treading the same mine field,
and depending upon its new MCZ-1 /70 to carry the day.
The MCZ-1/70 is billed as a multiterminal COBOL busi-
ness computer, although BASIC, FORTRAN, Pascal and
PLZ are listed as available languages. The primary thrust is
to provide a vehicle for the thousands of COBOL programs
that are running on aging number crunchers. The multi-
terminal capability (available only with COBOL) is just icing
on the cake.
A reliable 1 0-megabyte cartridge disk drive is the central
data storage device, but standard-size floppy disk drives are
available if you need them. Memory is limited to 64 kilo-
bytes, which must make things a little tight when all five CRT
terminals are alive. The terminals are Lear Siegler ADM-31
“smart” terminals with custom firmware programming.
Although Zilog is still sorting out their marketing distribu-
tion plans, a visit to their factory convinced us that they are
fully committed to producing a great many of these systems.
6800 SERIES OF EIGHT-BIT COMPUTERS
Smoke Signal Broadcasting Chieftain
The 9822 is a model of the Chieftain line that features a
6809 microprocessor board. 48 kilobytes of Random Access
Memory and a floppy disk controller in a nine-slot tabletop
housing. The boards conform to the SS-50 bus protocol
which was initially developed for the Motorola 6800 pro-
cessor. This particular Chieftain also comes with a dual full-
size floppy disk drive having a total capacity of nearly two
megabytes. An additional pair of such drives can be fitted,
along with the unlikely combination of four 514” minifloppy
disk drives, yielding up to 7.5 megabytes of storage total.
For a hard disk. Smoke Signal offers the clever Honeywell
hard disk drive that holds ten megabytes of information in its
small 8” removable cartridge. Using the new 32-kilobyte
RAM cards, up to 1 92 kilobytes of memory can be fitted into
the computer box.
The latter option will be needed when Smoke Signal intro-
duces its four-terminal multiuser operating system, soon to
be released to computer stores. Until then, you can purchase
at least one example of each of the major languages to run
on their single-terminal DOS 69 operating system.
SWTP S/09
The S/09 has continued as SWTP’s most successful
product since INTERFACE AGE reported on it last July. This
month we’ll highlight their System D, a remarkably complete
multiuser business computer system.
The System D is equipped with dual full-size dual-density
floppy disk drives that yield an impressive 2.5 megabytes of
online storage. But even that is simply an auxiliary to the
main bitbucket: a 16-megabyte Winchester hard disk unit.
Equally generous is the standard complement of 128 kilo-
bytes of main memory, which is allocated among the three
supplied CRT display terminals. The terminals are SWTP’s
74 INTERFACE ACE
JUNE 1980
More than meets the eye.
The new Series 5000 is mighty for its size.
In more than several thousand ways!
In fact, it’s the first small system offering over a
megabyte of integrated mini-floppy capacity. And
with its super memory management, you can. have
better than 300k of RAM in desk or desktop ver-
sions. But hardware is just the beginning of the story.
It’s the wide selection of software that really
makes this system mighty.
Operating systems? Choose CP/M* with
CBASICf — the most widely accepted small computer
operating system ever. Or MVT-FAMOS,** a multi-
user, multi-tasking operating system with file
management like the big guys, Or MICROCOBOL,tt
also for multiple users, but implemented in COBOL,
familiar to commercial users the world over.
And applications programs for these operating
systems number in the thousands. From real estate
to accounting, taxes to inventory control, they’re all
available at low cost — ready to run.
When you add these software and hardware
features to Industrial Micro Systems’ reputation for
rugged, reliable quality products you’ll begin to see it
all. A lot more systems than your first glance reveals.
See even more at your dealer. Call us to find
out the name of your nearest dealer. He’ll tell you
everything you need to know. And really open your
eyes!
Trademark ol Digital Research Inc. * ‘Trademark ol MVT Microcomputer Systems Inc.
tT rademark of Software Systems t fProduct of CAPCPP
INDUSTRIAL MICRO SYSTEMS
628 N. Eckhoff St., Orange, CA 92668, (714) 978-6966
2800 Lockheed Way, Carson City, NV 89701
JUNE 1980
CIRCLE INQUIRY NO. 34
INTERFACE AGE 75
own CT-82 design, one that definitely falls into the “smart”
category, even though the screen is limited to but 1 640
characters if lower case display is required.
All S/09 systems can be purchased with a good selection
of programming languages and aids, including what is billed
as the fastest BASIC ever for the 6809 chip. Multiterminal
operation is limited to the BASIC environment, a restriction
shared by Cromemco and some others in a list.
This product presents a good example of why you shouldn’t
select a computer by simply running your finger down the
price column. Even though $12,000 may sound like a stiff
tariff, it includes many essential items that must be purchased
as extras on many of the systems under review.
6502 SERIES OF EIGHT-BIT COMPUTERS
Computhink MINIMAX
The MINIMAX is a fresh computer design from a com-
pany that gained its reputation as a supplier of floppy disk
drives — 4000 shipped so far — to Commodore PET users.
The MINIMAX II is the larger of the two available versions,
offering 2.4 megabytes of storage capability in its dual 8”
flexible disk units. The machine is nicely packaged in a large
CRT terminal-style enclosure, and includes a remarkable
1 08 kilobytes of RAM internally. The display screen is able
to display high-resolution graphics, and some slick software
is included to produce charts, histograms and business forms.
Computhink is proud that it has produced all the software
that runs on the MINIMAX’s 6502 microprocessor. BASIC
and a machine language assembler are standard, with PLM
and FIFTH available. FIFTH was described to us as “a Pascal
derivative on FORTH.” On the applications side, the
MINIMAX offers an extensive DBMS subsystem and four of
the “big five” accounting packages as standard equipment.
Ohio Scientific C3
Ohio Scientific’s C3-C microcomputer system is absolute-
ly unique in that it features not one but all three of the eight-
bit micros under discussion: 6502, 6800 and Z80. The
6502 is the most completely supported in terms of Ohio
Scientific-supplied software, so we classify it in this group.
The C3-C was one of the first to marry a dual 8” floppy
disk drive with a single large-capacity Winchester disk and
market it as a package. The example was followed by several
others. The C3-C can be fitted with a copious supply of RAM
and an optional multiterminal operating system to allow up
to eight users to use the system simultaneously. In addition,
C3’s can be interconnected via a telecommunications net-
work to provide multiprocessing capabilities.
The Ohio Scientific catalog carries an almost embarrassing
array of applications programs, including games, personal
computing routines and educational packages. Only a few of
the listed programs seem appropriate to a serious business
environment, however, and they carry serious business prices.
IBM 5110
IBM’s eight-bit 5110 computing system does not use any
of the microprocessors listed in the previous pages, but an
internally-developed proprietary design. We place it here,
between the eight- and 1 6-bitters, because it has some of the
characteristics of both: eight-bit performance and a 16-bit
price. Actually, that’s a bit unfair to this gargantuan company
which is mother and father to business computing. Pur-
chasers of IBM products know they are paying a premium to
deal with a company that not only makes very few mistakes
in designing, building and marketing, but also boasts a
stability that is likely to outlast us all.
The 5110 is a floppy-disk based development on the
earlier 5100, which utilized proprietary cassette tapes for
data storage. Cassette drives are still available for the 51 10
for those who have a library of tapes to run on the earlier
model. The unit is housed in a neat tabletop enclosure look-
ing a lot like a large scientific electronic calculator. The small
size of the main computer is offset by a large floor-standing
rack-style cabinet needed to house the dual 8” floppy disk
drives. A second pair of drives can be fitted (bringing the total
capacity up to 4.8 megabytes), but they need their own iden-
tical enclosure.
In keeping with its small size, the display screen on the
5110 holds but 1 6 lines of 64 characters each. Applications
programs have to keep this limitation in mind. The machine
is the only one we know of in this size range which supports
the widely revered IBM-developed APL language.
Packaged solutions to business problems have always
been an IBM specialty, so we were not surprised to see a
selection of well-executed applications packages. They spe-
cialize in routines designed around a type of business (den-
tal, travel agency, etc.) rather than generally applicable ones
such as payroll — although the latter can be had as well.
Some of the software is rented by the month, rather than
licensed or sold outright.
1 6-BIT MICROCOMPUTERS
Alpha Micro AM-1 031
We’re moving into the “big iron” now in terms of size and
price. Expect a 1 6-bit computer to' offer something special in
terms of performance, and our first entry, the Alpha Micro-
systems AM- 1031 , is no disappointment. The machine is a
wayward child of DEC’s LSI-1 1 microcomputer, is inherent-
ly multiuser, multitasking, and multiterminal in its operation,
and is equipped with a wider array of development software
than any system we will cover.
The firm has nearly doubled its number of installed sys-
tems since October 1979 — most of them equipped with a
cartridge-type hard disk subsystem. Late last year, the com-
pany quietly began to upgrade the AM-100/T variant of its
basic AM-1 00 design. The event deserved more fanfare than
it occasioned, because the /T is in a new class in terms of
pure number crunching performance. No longer saddled
with eight-bit memory accesses, the new CPU talks to a true
16-bit RAM card at up to twice the previous rate. The
dynamic RAM itself features three extra bits per byte (for a
total of 1 1 ) which serve to correct all single-bit read errors
“on the fly.” Coupled with a 50% hop-up of the basic pro-
cessor speed, the AM-100/T performed our prime number
benchmark nearly twice as quickly as its predecessor.
The AM- 1031 is the mid-sized Alpha Micro. Its 10-mega-
byte Control Data Hawk cartridge disk drive has proven itself
to be more popular than both the floppy-based systems and
the ones equipped with the 90-megabyte Phoenix drive. A
single system can be fitted with any combination of these
data storage devices, offering more flexibility than a user will
probably ever need.
To programmers, the AM-1031 ’s most appealing feature
is the nearly 200 languages and utility programs that are
standard. BASIC is the primary applications language, and
Pascal, LISP and a macro assembler are included. Alpha-
BASIC is a semi-compiling language that leans towards busi-
ness applications with its COBOL-like data structures and
built-in ISAM capability. Alpha Micro also includes a really
slick screen-oriented text editor that can be used for word
processing applications as well as program entry. As far as
applications programs go, Alpha Micro dealers can serve up
a factory-supported package that incorporates general
ledger, accounts payable, accounts receivable, payroll and
order entry/inventory control.
Digital Microsystems HEX29
The heart of the HEX29 is not really a microprocessor at
all, but a brace of four AMD2900 bit-slice chips that team up
to provide a minicomputer-like broadside of 1 6-bit power.
The HEX29 fairly cooks, and this capability is further en-
hanced by its version of Pascal, which compiles programs
down into the machine language of the CPU itself, not in an
intermediate P-code as others do (see INTERFACE AGE,
Jan. 1 980, for an in-depth look at the HEX29).
76 INTERFACE ACE
JUNE 1980
If you can type, you
can handle
your accounting,
word processing
and much more
on ISC’s Small
Business Computer!
The lntecolor R 8963 is just one of a complete line of ISC
desktop computers designed for businessmen who don’t
know how- or don’t have time- to write programs. It's CP/M R
compatible, so you can choose from hundreds of CP/M
business programs— programs that have been proven in
hundreds of actual applications.
Programs like General Ledger, Accounts Receivable and
Payable, Payroll, Mailing List and Inventory Control are now
available in color. You’ll comprehend data faster, thanks to the
proven readability of ISC’s eight-color display.
To compose letters and other documents quickly and eas-
ily, you’ll want ISC’s unique color-coded Word Processing
program. With an optional printer, you can print out as many
mistake-free originals as you want!
The Intecolor 8963 is just $6395,* and includes a 19" color
graphics display, typewriter-like keyboard, dual disk drive for
data storage- even a color version of Microsoft” Business
BASIC for those of you who do want to program.
Don’t let your business get behind the times. Call your ISC
sales representative or visit your nearest Factory Authorized
ISC dealer and get a “hands on” demonstration today.
Color Communicates Better
* U S. domestic price Unretouched photo of screen. CP M is a registered trademark of Digital Research Corp
OEM Quantity Discounts are available to Qualified Dealers and Volume Users of 25 Systems (or greater) per year. Call your nearest ISC Representative listed below.
ISC SALES REPRESENTATIVES: AL: 205/883-8660, AZ: 602/994-5400, AR: (TX) 214/661-9633, CA: Alhambra 213/281-2280. Goleta 805/964-8751. Irvine 714/557-4460, Los Angeles 213/476-1241. Los
Altos 415/948-4563, San Diego 714 292-8525, CO: 303/355-2363, CT: 203/624-7800, DE: (PA) 215/542-9876, DC: (VA) 703/569-1502, FL: Ft. Lauderdale 305/776-4800, Melbourne 305/723-0766, Orlando
305/425-5505, Tallahassee 904/878-6642. GA: Atlanta 404/455-1035, HI: 808/524-8633. ID: (UT) 801/292-8145, IL: (No.) 312/564-5440. (So. MO) 816/765-3337, IN: (IL) 312/564-5440, IA: (Scott County
Only) 312/564-5440. (MO) 816/765-3337, KS: (MO) 816/765-3337, KY: 606/273-3771, LA: 304/626-9701. ME: (MA) 617/729-5770. MD: (VA) 703/569-1502, MA: 617/729-5770, Ml: Brighton 313/227-7067,
Grand Rapids 616/393-9839, MN: 612/645-5816, MS: (AL) 205/883-8660. MO: 816/765-3337, MT: (CO) 303/355-2363, NB: (MO) 816/765-3337. NH: (MA) 617/729-5770, NJ: (No.) 201 '224-691 1 . (So.)
215/542-9876. NV: (AZ) 602/994-5400, NM: 505/292-1212, NY: Metro/LI(NJ) 201/224-6911. N Syracuse 315/699-2651. Fairport 716/223-4490, Utica 315/732-1801, NC: 919/682-2383, ND: (MN)
612 645-5816. OH: Cleveland 216/398-0506. Dayton 513/435-7684, OK: (TX) 214/661-9633, OR: 503/644-5900. PA: (E) 215/542-9876, (W) 412/922-5110, Rl: (MA) 617/729-5770. SC: 803/798-8070. SD:
(MN) 612/645-5816, TN: 615/482-5761. TX: Austin 512/454-3579, Dallas 214/661-9633, El Paso Area (Las Cruces. NM) 505/524-9693, Houston Only 713/681-0200. UT: 801/292-8145. VT: (MA) 617/729-5770,
VA: 703/569-1502. WA: 206/455-9180. WV: (PA) 412/922-5110. Wl: (II ) 312/564-5440. WY: (CO) 303/355-2363.
EUROPEAN EXPORT SALES: EUROPE: (MA) 617/661-9424, BELGIUM: Brussels 02-242-36-04, DENMARK: 02-913255, FRANCE: Rueil Malmaison 749-47-65, Paris 33-1-306-4606. GREECE: Athens
642-1368, ITALY: Milano 02600733. THE NETHERLANDS: Poeldiik 01749-47640. Amsterdam 020-360904, SPAIN: Barcelona 204-17-43, SWEDEN: Vallingby 08-380-370, SWITZERLAND: Mutschellen
057-546-55. UNITED KINGDOM: Bournemouth 0201671181, WEST GERMANY: Koblenz 01 149-31025/6. AUSTRALIA & NEW ZEALAND: Auckland 876-570, Canberra 58-1811, Chermside 59-6436,
Christchurch 796-210, Melbourne 03-543-2077, Sydney 02-808-1444, Wellington 644-585, CANADA: Dorval 514/636-9774, Ottawa 613/224-1391, Toronto 416/787-1208, Vancouver 604/684-8625, CENTRAL
AND SOUTH AMERICA & CARIBBEAN: (GA) 404/394-9603, MEXICO: Monterrey 564-876. FAR EAST: (CA) 213/382-1 107, HONG KONG: 5-742211 JAPAN: (Tokyo)
(03) 463-9921. TAIWAN: (Taipei) 02-7026284. MIDDLE EAST: (GA) 404/581-0243, EGYPT: 809933. ISRAEL: Ramat Gan 03725749,
KUWAIT: Kuwait 438-180/1/2. LEBANON: Beirut 221731/260110, SAUDI ARABIA: Jeddah 27790. Riyadh 25083-39732
For sales and service in other countries contact ISC headquarters in Norcross. GA., U S A.
^9 Intelligent Systems Corp.'
Intecolor DriveD 225 Technology Park/ Atlanta □ Norcross, GA 30092 □ Telephone 404/449-5961 CDTWX 810-766-1581
CIRCLE INQUIRY NO. 38
In brief, this machine can hold up to two megabytes of
error-correcting Random-Access Memory to be utilized by
up to 32 different users simultaneously. Only single-sided,
single-density floppy disk drives can be fitted, but Digital
Microsystems makes up for that in part by allowing more
drives than one will probably use. Actually, the optional
28-megabyte hard disk drive is a “must” for business appli-
cations with this powerful system.
The standard BASIC interpreter includes ISAM capability;
FORTRAN is also available. The supplied line-oriented text
editor rates only fair in the ease-of-use category when com-
pared to the marvelous screen-oriented designs that are be-
coming commonplace. The HEX29 has no factory-supported
applications programs.
Rexon RX30
Rexon stands apart from most of the vendors in this review
due to its IBM-like approach to selling computer systems.
The RX30 is a machine that you buy as a whole, including
installation, maintenance support and, most likely, an inte-
grated set of applications programs assembled by the Rexon
dealer. This marketing approach is, of course, older than the
microprocessors themselves, but is often accompanied by
serious compromises in the performance of the computer
itself. Not so with the RX30, in large part because it is con-
structed around the state-of-the-art 1 6-bit 8086 micro. It’s
the first such implementation we’ve seen, and it looks to be
the first of many such applications for this powerful chip.
A 20-megabyte cartridge-type hard disk drive is the only
mass storage device available on the RX30. Floppy disks
were thought to be inappropriate to this class of machine.
That’s powerful stuff, coming as it does from Dr. Wang, Rex-
on’s president and single-handed developer of much of
today’s floppy drive technology.
The RX30 is a BASIC-only computer in the mold of
Basic/Four. It’s far simpler for a programmer to compre-
hend than, say, the complex structure of the Alpha Micro
computer. The limitations in flexibility inherent with this
approach are somewhat offset by the ease of training and
programming debugging. The most spectacular item in Rex-
on’s software lineup is IDOL, a combination DBMS and pro-
grammer’s aid. It’s conceivable that one could make a career
of writing business applications without ever learning to pro-
gram in BASIC; simply by using the capabilities of IDOL
alone. Most of the RX30’s applications software comes via
the factory-sponsored dealer Software Exchange. The
catalog has over 1 00 pages and is growing steadily.
Technico SS-16
The SS-16 computer is the only one in our list that utilizes
the Texas Instruments’ TMS9900 16-bit microprocessor
chip. Technico has a good thing all to itself so long as their
competitors continue to shun this extremely capable device.
Technico has its roots in the industrial process control field,
and is only recently making its product available in business
garb. The TAS-MU-DFD is an SS-16 with 64 kilobytes of
RAM and a dual 8” floppy disk drive housing a half-megabyte
of storage capacity. Winchester-technology hard disk drives
can be added to give up to 40 megabytes more of data storage.
A multiuser operating system, which is standard, allows up
to 18 terminals to be connected simultaneously. Actually,
there are limitations. Space restrictions in the CPU box hold
you to 12 users if 192 kilobytes of RAM are fitted, or six
users with 224 kilobytes. It would be hard to call that a
serious shortcoming.
Since February, Technico has released packages to handle
all of the “big five” business applications, in addition to a
date base manager. Although it has traditionally been a bit
behind the times in the area of word processing, Technico is
about to release a blockbuster. We were sworn to secrecy re-
garding most of the details, but. . .would you believe —
multicolored entry?
Three Rivers Computer PERQ
it is appropriate that our review close with PERQ, since it
embodies what might become the future of small business
computers. The PERQ (pronounced “perk,” not “pur-que”)
borrows almost nothing from the designs arrayed before you
in this issue; it strikes out into territory that was previously ex-
plored only in the thought experiments of advanced think-
tank operations.
PERQ is intended to be the all-in-one work station of the
electronic office of tomorrow. Its powerful computing cap-
abilities are optimized to provide local problem-solving
power as well as intercommunication with a shared-resource
network consisting of other PERQs and larger systems. It is
inherently multitasking, but these tasks are designed to serve
the single person who sits at its keyboard. This person is
served by a quarter megabyte of RAM and 1 2 megabytes of
hard disk storage as well.
The display terminal is unique. Three Rivers Computer
has applied its expertise in high-resolution display tech-
nology to serve up a CRT, which can speak in a dozen dif-
ferent type faces, with proportional justification thrown in for
good measure. The screen can be divided into several win-
dows, each showing the status of the various multiprocesses
that the computer performs. The display is oriented vertically
like a sheet of typewriter paper, and is ideally adapted to
word processing entry. Actually, the PERQ looks beyond
word processing as we know it today to the future when the
vast majority of written communication will be transmitted
electronically. Why clutter up your office with paper when
everyone you correspond with has a PERQ-like machine to
receive your communications via satellite signals?
The PERQ also features a Touch Table that translates pen-
cil or finger pressure directly into signals to direct the cursor
on the display screen. A speech output module is also stan-
dard equipment.
The Three Rivers product utilizes a proprietary 1 6-bit pro-
cessor design which has the native language of Pascal
P-code. This is an optimized-efficiency approach which is
sure to be quite common in 1 990s-vintage systems. No
other language is available or needed on the PERQ.
The PERQ is definitely in that class of “solutions looking
for a problem” machinery. The biggest threat to its probable
success would be users who lack the imagination to apply
mind-stretching capabilities properly.
The power of the computer systems represented here
seems almost commonplace today. Only a few years ago
they were misunderstood toys gracing the offices of a few
forward-thinking business people. Most of us were left to
play catch-up; and some, it is sad to say, remain ignorant of
the rewards available to those who would make a home in
their businesses for a computer system. □
ABOUT THE AUTHOR
Tom Fox has twenty years
experience in the field of elec-
tronics, thirteen years in com-
puter systems and their appli-
cation to business and indus-
try . President of Fox Ware
Systems Corporation , of Ir-
vine , California, he is also
past Director of Engineering
at Structured Micro Systems,
Inc., where he headed up the
development of a computerized telephone answering ser-
vice and centralized alarm monitoring system. He can be
reached at 17925-G Sky Park Circle, Irvine, CA 92714,
telephone (714) 957-9331.
78 INTERFACE AGE
JUNE 1980
PEARL”!
Skeptics are still saying a program like PEARL
won’t be available until the mid-1980s
They’re wrong, of course. PEARL is available now.
PEARL (Producing Error-free Automatic Rapid Logic) brings application generation software to microcomputer
users at four user levels.
Very simply, PEARL means that anyone with a microcomputer with 48K memory can use one of the four PEARL
programs to generate new applications software with a minimum of time, trouble and training.
PEARL runs under CP/M* and is designed as a powerful menu-driven tool. PEARL Level 1 provides
non-programmers with the capability to program their own new applications automatically. Users respond to
on-screen prompts as they define their system; no programming knowledge is required.
PEARL Levels 2 and 3, for experienced programmers, provide sophisticated processing for complex
applications. In just fractions of the time it used to take to design, code, and test a program, PEARL will generate and
compile a new application. PEARL Level 4, the most advanced of the PEARL packages, provides programmers with
the capability to include many features normally associated with customized turnkey systems.
Introductory prices. Trade-in allowances for upgrade to higher levels.
PEARL Level 1
For Personal Computing
$ 90
PEARL Level 2
The Business Assistant
$ 200
PEARL Level 3
For Software Developers
$ 400
May 1 980
PEARL Level 4
For Turnkey Systems Developers
$ 800
June 1980
volulionarv software for
the
1980s
Computer Pathways Unlimited, Inc.
Corporate Office: 2151 Davcor Street S.E.
Salem, Oregon 97302
503 - 363-8929
CIRCLE INQUIRY NO. 13
*CP/M is a trademark of Digital Research
THE
COMPARISON
TABLES
EXPLAIN
By Tom Fox
Systems Editor
Like the smorgasbord at a Swed-
ish wedding reception, the tables
on the following pages are fairly
laden with tasty morsels that are the
visible fruits of a small army of
behind-the-scenes artists. The
creators of the masterpieces arrayed
before you do not practice their
skills in the kitchen, but in the de-
velopment labs that are the most
guarded corners of the many com-
puter factories represented here.
The six tables of data can help in
comparing various aspects of the
systems we are looking at this
month. Most of the information is
self-explanatory, but some of the
categories can be a little tricky. This
is mainly due to the fact that tabu-
lar headings that do a good job of
describing one manufacturer’s sys-
tem are often inadequate to de-
scribe another. Each system has
unique properties not shared by
any of the others. We did the best
we could, and personally checked
with each manufacturer to make
sure all of the entries are up-to-date.
Keep in mind as you read: “n/a”
means “information not available’
or, in some cases, “refused.’’
TABLE 1 - HARDWARE DATA
This chart carries general infor
mation about the hardware ele
ments of the system. Most import
antly, it lists a model number,
price, and tells what major com-
ponents are included in that price.
In this and the following tables, the
indication “Std” means the hard-
ware or software item is included
as standard equipment at the
quoted price. “Opt’’ indicates the
item is optional at extra cost. If the
extra dollar amount was made
available, we included it.
Under “ENCLOSURE,’’ we indi-
cate if the computer is supplied in a
free-standing tabletop housing, is
integrated into a desk-style work
station, is equipped for rack mount-
ms m
ing, or a combination of these. The “BUS” column
tells us if the plug-in-cards that make up the computer
conform to a known industry standard. You can, in
theory, interchange different manufacturers’ circuit
boards if they both conform to the same bus protocol.
This is done every day, but be warned that the
maneuver is sometimes doomed because of minute
discrepancies among the various designs.
“RAM” stands for random access memory, the fast
semiconductor memory element utilized by all of the
systems we are reviewing this month. The amounts are
shown in kilobytes, or thousands of bytes. (A byte is
equivalent to the amount of storage required to remem-
ber a single character, such as “A”.) All of the systems
we are looking at are equipped with one or more disk
drives, either of the flexible diskette (“floppy”) variety,
or the higher-performance hard disk drive. Some sys-
tems come complete with both; the floppy drive often
included as a means to create backup copies of data
on Winchester-technology hard disk drives. Other
than the obvious advantage of having more storage
space, hard disk drives are commonly several times
faster than the floppy variety.
In Table 1 is an indication as to whether or not a
cathode-ray tube (CRT) display terminal or hard copy
printer is included in the basic price. Several of the
manufacturers do not provide these devices at all;
they let the local dealers buy them separately and inte-
grate them into a system before delivering the assem-
blage to the ultimate user. The peripheral devices can
form a significant fraction of the purchase price, so take
that into account when comparing system costs.
TABLE 2 - DISK DRIVE DATA
Here we take a closer look at that most critical element
of a computer system: the mass storage device. Shown
is the number of drives supplied as standard, and the
maximum size that can be fitted in the future. Capaci-
ties are shown in kilobytes for
megabytes (millions of bytes)
Remember that 1,000 kilobytes equal one megabyte.
All floppy disk drives are built to allow you to
remove the diskette itself aid store it away for
safekeeping or to maintain a library of programs, data,
etc. It’s of critical importance that at least one extra
copy of each diskette be maintc ined as well. There are
the floppy disk drives;
in the hard disk case.
achine errors that can
to be destroyed with
several kinds of human and m<
cause the data on a diskette
alarming ease. The activity o; : creating the backup
copy requires that at least two diskette drives be fitted
to the computer system, the master being copied from
and the ‘ scratch” disk being copied onto.
The sane principles, of course, apply to hard disk
drives. In this case, however, the amount of data that
can accicentally be destroyed is much greater. Hard
disks listed as the “cartridge” type in Table 2 contain
a certain amount' (usually half) of their storage on an
internal, non removable disk platter. The cartridge
itself is a removable disk that can be inserted into the
drive to back up the data contained on the non-
removable one. Backup copies of critical data are thus
nearly as easy to make as the floppy disk systems.
Winchester-technplogy hard disks are fundamentally
different, in that all data is contained on a non-
removable disk platter. Winchester devices contain
their spinning disk within a hermetically sealed en-
vironment and any data copies must be made onto
some other external device; ta some cases, floppy disk
drives; in others, | special magnetic tape units. Win-
chester technology offers today’s best bargain in
bytes-per-buck storage, but the world is still waiting
for someone to solve the knotty problem of backing
up the data in a cortvenient, economical manner.
Many simply skip the backup process — an invitation
to disaster, in our opinion.
It may be nit-picking, but we’ve noticed that compu-
ter salesmen are beginning to list the “unformatted”
capacity of their disk drives rather than the “formatted”
or usable quantity. A certain portion of each disk or
floppy diskette is occupied with “housekeeping” data,
so all of that space isn’t really available for your own
use. (An example: One manufacturer’s implementation
of the popular Shugart SA-4000 Winchester drive re-
quires 6 megabytes of the disk’s 29-megabyte capac-
ity for internal formatting information, leaving but 23
megabytes for your use.) We have tried mightily to list
only the formatted capacity in Table 2, but in a few
cases, even the factory representatives didn’t know!
TABLE 3 - PERIPHERALS DATA
In this chart, we have gathered together the last of
the hardware-related information. Each of the systems
utilizes some form of a CRT display terminal for
primary data input and output, although some are
priced separately. A few have a graphics capability in
addition to the basic ability to display letters and
numbers. The MAXIMUM QUANTITY column indi-
cates how many terminals can be connected to the
system simultaneously in a multi-user environment.
A printer is an essential part of any business com-
puter system. Two of the columns in Table 3 briefly
describe those available. Matrix printers form the
characters on the page as a collection of tiny dots.
They are usually faster, less expensive and more
reliable than character printers, but are not suitable
for word-processing applications if you want the final
result to appear as if it were produced on a typewriter.
Fully formed character printers make theirlmage like
a typewriter, with a single stroke. Nearly all character
printers are of the spinning daisywheel or thimble
variety, which represent a real performance advance-
ment over the earlier tumbling golf ball technology of
IBM’s Selectric. Printer speeds are shown as the aver-
age number of characters produced per second (cps)
or, in some cases, the number of complete lines of text
printed per minute (Ipm). Don’t be concerned if the
chart comes up “none” in both the STANDARD and
OPTIONAL categories. This just means that the local
dealer must buy directly from the printer manufacturer,
the same as the computer manufacturer.
The final column in Table 3 is a catch-all for the
special and unique hardware attachments that form a
large part of a computer’s personality. We didn’t list
the serial and/or parallel interfacing port options.
TABLE 4 - SYSTEM SOFTWARE DATA
System software includes programs normally pro-
vided by the manufacturer to manage the central func-
tion of moving data around among the computer
memory, disk, printer, and terminal(s). It also includes
software than can be utilized by programming person-
nel to create usable application programs (listed on
the next chart). We have made a special effort to
research the prices for software, to highlight the signi-
ficant cost that can be represented by this category of
investment. If having a large library of purchasable
programs is important in your business, pick a system
that can run with one of the widely used operating
systems. CP/M leads the pack in this race, but several
others follow closely.
Column headings are included for the four most
popular programming languages (BASIC, COBOL,
FORTRAN and Pascal) as well as the assembler which
can produce runnable programs in the native language
82 INTERFACE ACE JUNE 1980
Table 1. Hardware Data
BASIC
ENCLOSURE
CPU
RAM
STANDARD PERIPHERALS
MANUFACTURER
SYSTEM
PRICE
TABLETOP
DESK
RACK
TYPE
BITS
BUS
STD
MAX
DISK DRIVE
TERMINAL
PRINTER
Alpha Micro
AM-1031
$17,835
Std
No
Opt
WD16
16
S-100
64 K
1024K
1 Hard
No
No
Altos
ACS8000-6/MU4
$11,960
Std
No
No
Z80
8
None
208 K
208 K
2 Floppy*
1 Hard
No
No
Computhink
MINIMAX II
$ 9,200
Std
No
No
6502
8
None
108K
108K
2 Floppy
Yes
No
Cromemco
System 3
$ 6,990
Opt
Opt
Std
Z80
8
S-100
64 K
512K
2 Floppy
No
No
Digital Microsystems
HEX29
$15,900
Std
No
No
2900
16
Prop.
256 K
1000K
2 Floppy
No
No
Heath
WH89-CS
$ 2,895
Std
No
No
Z80
8
None
48 K
48 K
1 Floppy
Yes
No
IBM
5110
$19,475
Std
No
Std
Prop.
8
Prop.
32 K
64 K
2 Floppy
Yes
No
IMS
Series 8000
$ 4,500
Std
Opt
Opt
Z80
8
S-100
32K
256K
2 Floppy
No
No
Intertec
SuperBrain
$ 2,995
Std
No
No
Z80
8
None
32K
64 K
2 Floppy
Yes
No
Micro V
MicroStar 1
n/a
Std
Opt
No
8085
8
None
64K
64K
2 Floppy
No
No
MicroDaSys
millie
$ 3,999
Std
Opt
No
Z80
8
S-100
48K
60 K
1 Floppy
Yes
No
North Star
HRZ-2-64K-D
$ 5,820
Std
No
No
Z80
8
S-100
64K
64K
2 Floppy
Yes
Yes
Ohio Scientific
C3-C
$ 9,900
No
No
Std
6502
8
Prop.
48 K
384 K
2 Floppy*
No
No
Z80
8
1 Hard
6800
8
Pertec
PCC 2000
$ 9,995
Std
No
No
8085
8
P-100
64K
64K
2 Floppy
Yes
No
Radio Shack
TRS-80 Model II
$ 3,899
Std
Opt
No
Z80
8
Prop.
64 K
64 K
1 Floppy
Yes
No
Rexon
RX30
$32,500
No
No
Std
8086
16
Prop.
64 K
128K
1 Hard
Yes
Yes
Smoke Signal
9822
$ 4,344
Std
Opt
Opt
6809
8
SS-50
48 K
192K
2 Floppy
No
No
SWTP
System D
$12,000
Opt
Std
No
6809
8
SS-50
128K
768K
2 Floppy*
1 Hard
Yes (3)
No
Technico
TAS-MU-DFD
$ 7,895
Std
No
Opt
9900
16
Prop.
64 K
224K
2 Floppy
No
No
TEI
3400
n/a
No
Std
No
8085
8
S-100
64K
64K
2 Floppy
Yes
No
Three Rivers Computer
PERQ
$19,500
Std
No
Std
Prop.
16
Prop.
256 K
1000K
1 Hard
Yes
No
Vector Graphic
System B
$ 5,463
Std
Opt
No
Z80
8
S-100
56 K
56 K
2 Floppy
Yes
No
Zilog
MCZ-1/70-2
$19,835
No
No
Std
Z80
8
Z-bus
64K
64 K
1 Hard
Yes
No
Table 2. Disk Drive Data
MANUFACTURER
SYSTEM
NUMBER OF DRIVES/TOTAL CAPACITY (bytes)
FLOPPY DISKETTE
HARD DISK
SIZE
STD
MAXIMUM
TYPE
STD
MAXIMUM
Alpha Micro
AM-1031
8”
None
8/9600 K
Cartridge
1/10M
4/360 M
Altos
ACS8000-6/MU4
8”
2/1000K
4/8000 K
Winchester
1/14M
2/58 M
Computhink
MINIMAX II
8”
2/2400K
2/4800K
—
None
—
Cromemco
System 3
8”
2/1024K
4/2048 K
Winchester
None
4/40 M
Digital Microsystems
HEX29
8”
2/512K
8/2048K
Winchester
None
2/56 M
Heath
WH89-CS
5V4”
1/1 00K
1/1 00K
—
None
—
IBM
5110
8”
2/2400 K
4/4800K
—
None
—
IMS
Series 8000
8”
2/486 K
4/3856 K
Cartridge
None
2/180M
Intertec
SuperBrain
5V4 m
2/265K
2/700K
Winchester
None
4/72 M
Micro V
MicroStar 1
8”
2/2000K
4/4000K
Winchester
None
1/20 M
MicroDaSys
millie
8”
1/500K
4/2000K
Cartridge
None
4/90 M
North Star
HRZ-2-64K-D
5V4”
2/360 K
4/1440K
Winchester
None
4/72 M
Ohio Scientific
C3-C
8”
2/544K
2/1088K
Winchester
1/23M
1/23 M
Pertec
PCC 2000
8”
2/1200K
2/1200K
Cartridge
None
4/80 M
. Radio Shack
TRS-80 Model II
8”
1/486K
4/1944K
—
None
—
Rexon
RX30
—
None
—
Cartridge
1/20M
2/40 M
Smoke Signal
9822
8”
2/2000 K
8/7500 K
Cartridge
None
1/20 M
SWTP
System D
8”
2/2500 K
4/5000K
Winchester
None
1/16 M
Technico
TAS-MU-DFD
8”
2/512K
4/1 024 K
Winchester
None
4/40 M
TEI
3400
8”
2/1986K
8/7944K
Winchester
None
32/442M
Three Rivers Computer
PERQ
8”
None
1/1024K
Winchester
1/12M
1/24 M
Vector Graphic
System B
5V4”
2/630K
4/1 260 K
—
None
—
Zilog
MCZ- 1/70-2
8”
None
4/1 200 K
Cartridge
1/10M
4/40 M
of the microprocessor itself. Under OTHERS, we list addi-
tional programming languages and major utilities that ease
the applications programmer’s task. In addition, all of the sys-
tems make available some kind of a text-entry capability for
keying in the source programs in the various languages.
TABLE 5 - APPLICATIONS SOFTWARE DATA
Taken as a whole, writing applications programs for com-
puters is a massive task, occupying a rapidly increasing frac-
tion of the world’s workforce. There is a snowballing trend
for computer manufacturers to deliver their machines with
useful programs that can be put to use right away. Their in-
tent is to apply some standardization to programs which are
run on their products, and to remove a significant barrier to
their sales. The effort is ambitious and well-motivated. To be
successful, the programs themselves must be very nearly
perfect and generally applicable in a wide variety of applica-
tions situations.
Table 5 lists the major applications packages that are avail-
able from the various manufacturers. The “big five” are
there (general ledger, accounts payable, accounts receivable,
payroll and order entry /inventory control), as are a pair of
applications that are becoming featured by more and more
computers these days: word processing and data base
management system (DBMS).
Modern word processing programs consist of two parts: a
means to enter textual data from a CRT terminal, and a way
to transform the information and send it to a hard-copy
printer. Many of the word processors feature a “screen-
oriented” editor for data entry which is rapidly becoming
today’s state-of-the-art.
First-time computer users who have never uttered the
acronym DBMS often find it soon becomes the most used
program in the machine. Applied intelligently, a good
DBMS can organize everything from the annual report to
your daily appointment calendar. There is little standardiza-
tion in DBMS programs, so make sure the one you purchase
is appropriate to the size and complexity of your needs.
TABLE 6 - CORPORATE DATA
The final chart in the series zeroes in on the companies
that make the computer systems being reviewed in this issue.
Included are size, age, and retail outlet base, as well as the
manufacturing history of the system itself. GROSS SALES
are for the most recent complete business year and include
the receipts of any parent company. Also shown are the cur-
rent number of retail outlets and service centers, if different.
The final two columns tell the birthdate and total number
delivered of the system being reviewed in this issue. In a few
cases, we have allowed the manufacturer to include nearly
identical predecessors of the reviewed system if the dif-
ferences are small and evolutionary.
We will let you roam through the tables like the guest at a
Swedish wedding reception, comparing the relative merits of
each dish and selecting the one that suits your taste. We
make no recommendations as to which might be best, as
each and every one of them will be the optimum choice
given a particular business situation. Assembling this mass of
data was the easy part. The difficult task, now, is yours:
choosing the system that enables your business to run more
smoothly and profitably. □
JUNE 1980
INTERFACE AGE 83
84 INTERFACE AGE JUNE 1 980
Table 3. Peripherals Data
MANUFACTURER
SYSTEM
CRT DISPLAY TERMINAL
PRINTER TYPE/SPEED
OTHER
PACKAGE
GRAPHICS
CHARACTERS
MAX QTY
STANDARD
OPTIONAL
Alpha Micro
AM-1031
Separate
No
1920
12 +
None
None
Real-time Clock (Std)
Magnetic Tape
ASYNCH/SYNCH
Communications
Altos
ACS8000-6/MU4
Separate
No
1920
4
None
None
Magnetic Tape
Floating Point
Computhink
MINIMAX II
Integrated
Std
1920
1
None
Matrix/60 cps
Matrix/150 cps
None
Cromemco
System 3
Separate
No
1920
7
None
Matrix/60 cps
Matrix/180 cps
Character/55 cps
PROM Programmer
Color Graphics
A/D & D/A
Digital Microsystems
HEX29
Separate
No
1920
32
None
Matrix/150 cps
Matrix/300 cps
None
Heath
WH89-CS
Integrated
No
1920
1
None
Matrix/40 cps
Matrix/150 cps
Character/45 cps
None
IBM
5110
Integrated
No
1024
1
None
Matrix/80 cps
Matrix/120 cps
Mag Tape Cartridge
BISYNCH Comm.
ASYNCH Comm.
IMS
Series 8000
Separate
No
1920
8
None
None
None
Intertec
SuperBrain
Integrated
No
2000
1
None
None
S-100 Bus Adapter
Micro V
MicroStar 1
Separate
No
1920
2
None
Matrix/1 12 cps
Matrix/300 Ipm
Character/55 cps
None
MicroDaSys
millie
Separate
Opt
2000
1
None
Character/55 cps
Color Graphics
North Star
HRZ-2-64K-D
Separate
No
1920
1
Matrix/112 cps
Character/55 cps
Floating Point
Ohio Scientific
C3-C
Separate
No
1920
8
None
Matrix/110 cps
Matrix/125 Ipm
Character/55 cps
Networking
B/W Graphics
Pertec
PCC 2000
Integrated
Std
1920
5
None
Matrix/120 cps
Character/55 cps
None
Radio Shack
TRS-80 Model II
Integrated
Std
1920
1
None
Matrix/60 cps
Matrix/120 cps
Character/50 cps
None
Rexon
RX30
Separate
No
1920
8
Matrix/150 cps
Matrix/300 Ipm
None
Smoke Signal
9822
Separate
No
1920
1
None
Matrix/165 cps
B/W Graphics
SWTP
System D
Separate
Std
2024
16
None
Matrix/60 Ipm
Matrix/120 cps
Character/45 cps
None
Technico
TAS-MU-DFD
Separate
No
1920
18
None
Matrix/180 cps
A/D & D/A
RAM Battery
TEI
3400
Separate
No
2000
1
None
Matrix/150 cps
None
Three Rivers Computer
PERQ
Integrated
Std
5490
1
None
Matrix/300 Ipm
Character/45 cps
Touch Tablet (Std)
Speech Output (Std)
GPIB Interface (Std)
Networking
Vector Graphic
System B
Separate
No
1920
5
None
Matrix/150 cps
Character/55 cps
A/D & D/A
B/W Graphics
Video Digitizer
Zilog
MCZ-1/70-2
Separate
No
1920
5
None
Matrix/140 cps
Character/55 cps
None
JUNE 1 980 INTERFACE AGE 85
Table 4. Systems Software Data
MANUFACTURER
SYSTEM
OPERATING SYSTEM
PROGRAMMING LANGUAGES
SINGLE-USER
MULTI-USER
ASSEMBLER
BASIC
COBOL
FORTRAN
PASCAL
OTHERS
Alpha Micro
AM-1031
None
AMOS
Std
Std
No
No
Std
LISP (Std)
ISAM (Std)
SORT (Std)
Altos
ACS8000-6/MU4
CP/M $150
AMEX $600
$100
$150
$750
$500
$200
OASIS $500
APL $500
KSAM $450
Computhink
MINIMAX II
DOS
None
Std
Std
No
No
No
PLM
FIFTH
Cromemco
System 3
CDOS
Multi-user
BASIC $800
$95
$95
$95
$95
No
RATFOR $195
TRACE $95
Struct. BASIC $295
Digital Microsystems
HEX29
None
HOST
Std
Std
No
Opt
Opt
ISAM
Heath
WH89-CS
H-DOS $100
None
Std
Std
No
No
No
Microsoft BASIC $100
IBM
5110
n/a
None
No
Std
No
No
No
APL $1000
Sort Utility
Subroutine Library
IMS
Series 8000
CP/M
FAMOS $1500
Opt
$100
Opt
Opt
Opt
OMNIX $350
CAP-CPP
CBASIC $500
Intertec
SuperBrain
CP/M
None
Std
$350
No
$500
No
None
Micro V
MicroStar 1
None
StarDOS
Opt
Std
Opt
Opt
Opt
CP/M
CAP-CPP
MicroDaSys
millie
CP/M
None
Std
Std
$600
$400
$350
CBASIC $100
Microsoft BASIC $300
North Star
HRZ-2-64K-D
NS/DOS
None
No
Std
No
No
$199
None
Ohio Scientific
C3-C
OS-65/ U
Level 3 $400
Std
Opt
Opt
Opt
Opt
OS-CP/M $600
Pertec
PCC 2000
DOS
MTX
No
Std
Opt
Opt
No
CP/M
Radio Shack
TRS-80 Model II
TRSDOS
None
No
Std
No
No
No
None
Rexon
RX30
None
RECAP
No
Std
No
No
No
IDOL
Smoke Signal
9822
DOS 69
None
$40
$100
Opt
$150
$250
Compiler BASIC $325
SWTP
System D
FLEX-09
Multi-user
BASIC $150
$40
$65
No
No
$250
DEBUG $75
Sort/Merge $75
PILOT $250
Technico
TAS-MU-DFD
None
MU/OS
Std
Std
No
$990
No
1 1 A (Std)
TEI
3400
TDOS
None
Opt
Opt
Opt
Opt
No
SORT (Std)
Three Rivers Computer
PERQ
None
DOS
No
No
No
No
Std
Symbolic Debugger
Screen Window Mgr.
Vector Graphic
System B
CP/M
Timeshare
Monitor $250
Std
Std
$500
No
No
UNIVIS (Std)
APL $400
ASYNCH Comm. $150
Zilog
MCZ-1/70-2
None
RIO
Std
$500
$850
$950
$950
PLZ $500
ASYNCH Comm. $500
86 INTERFACE AGE JUNE 1 980
Table 5. Applications Software Data
MANUFACTURER
SYSTEM
WORD
PROCESSING
DBMS
G/L
A/P
A/R
PAYROLL
INVENT.
CONTROL
OTHERS
Alpha Micro
AM-1031
Std
No
Opt
Opt
Opt
Opt
Opt
None
Altos
ACS8000-6/MU4
$500
No
No
No
No
No
No
None
Computhink
MINIMAX II
No
Std
Std
Std
Std
Std
No
None
Cromemco
System 3
$95
$95
No
No
No
No
No
Multi-user DBMS $195
Digital Microsystems
HEX29
No
No
No
No
No
No
No
None
Heath
WH89-CS
$495
No
No
No
No
No
No
None
IBM
5110
No
No
$75/mo
$75/mo
No
$80/ mo
No
Travel Agency Accounting
Mortgage Closing
Client Accounting
Dental Accounting
IMS
Series 8000
$150
Opt
Opt
Opt
Opt
Opt
Opt
WordStar $495
Apartment Management
Intertec
SuperBrain
No
No
No
No
No
No
No
None
Micro V
MicroStar 1
Opt
Std
Opt
Opt
Opt
Opt
Opt
Mail List
MicroDaSys
millie
$275
$125
$99
$99
$99
$99
No
WordStar $495
Medical Billing $895
Pencil Sharpener $195
Star Brightener $150
North Star
HRZ-2-64K-D
No
No
No
No
No
No
No
None
Ohio Scientific
C3-C
$200
$300
$300
$300
$300
$300
$300
Educational Pkg.
Purchasing
Estimating/Quotation
Bill of Materials
Mail List
Pertec
PCC 2000
No
No
Opt
Opt
Opt
Opt
Opt
None
Radio Shack
TRS-80 Model II
No
No
$199
No
$299
$399
$199
Mail List $79
Rexon
RX30
No
Std
No
No
No
No
No
None
Smoke Signal
9822
$80
No
Opt
Opt
Opt
Opt
Opt
None
SWTP
System D
$35
No
$595
$600
$600
No
$100
Mail List $50
Shipping/Receiving $75
Technico
TAS-MU-DFD
Opt
Std
$2000
Opt
Opt
$1000
Opt
None
TEI
3400
No
Opt
No
No
No
No
No
None
Three Rivers Computer
PERQ
Std
No
No
No
No
No
No
None
Vector Graphic
System B
$450
$350
Std
Std
Std
Std
Std
None
Zilog
MCZ- 1/70-2
No
No
No
No
No
No
No
None
Table 6. Corporate Data
SERVICE
REVIEWED SYSTEM
GROSS
DEALERS
CENTERS
FIRST
TOTAL
MANUFACTURER’S ADDRESS
SALES
ESTAB.
US
FOREIGN
US
FOREIGN
DELIVERY
QTY
Alpha Microsystems
17881 Sky Park North
Irvine, CA 92714
$17M
1977
170
30
10
30
Apr 1977
4000
Altos Computer Systems
2360 Bering Drive
San Jose, CA 95131
$10M
1977
100
300
100
300
Jan 1975
5000
Computhink
965 W. Maude Avenue
Sunnyvale, CA 94086
n/a
1978
25
75
25
75
Sep 1979
300
Cromemco, Inc.
280 Bernardo Avenue
Mountain View, CA 94040
n/a
1974
107
38
107
38
Feb 1978
2000 +
Digital Microsystems
4448 Piedmont Avenue
Oakland, CA 94611
n/a
1975
n/a
n/a
n/a
n/a
Dec 1979
20
The Heath Company
Benton Harbor, Ml 49022
n/a
1926
55
n/a
55
n/a
Aug 1979
n/a
IBM/General Systems Division
4111 Northside Parkway
Atlanta, GA 30301
S2.3B
1924
n/a
n/a
n/a
n/a
n/a
n/a
Industrial Micro Systems
628 N. Eckhoff Street
Orange, CA 92688
$4M
1975
75
25
75
25
Jul 1979
1000
Intertec Data Systems
2300 Broad River Road
Columbia, SC 29210
$6M
1973
250
30
50
50
Oct 1979
4000
Micro V Corporation
17777S.E. Main Street
Irvine, CA 92714
n/a
1978
40
35
40
9
Sep 1978
600
MicroDaSys
P.O. Box 36051
Los Angeles, CA 90036
$1 M
1977
200
10
5
5
Feb 1979
125
North Star Computers
1440 Fourth Street
Berkeley, CA 94710
n/a
1976
200
100
200
100
Dec 1977
10000
Ohio Scientific
1333 S. Chillicothe Road
Aurora, OH 44202
n/a
1975
175
25
2
0
Jan 1979
n/a
Pertec Computer Corporation
12910 Culver Boulevard
Los Angeles, CA 90066
$148M
1967
100
35
30
35
Jan 1979
1500
Radio Shack
1300 One Tandy Center
Fort Worth, TX 76102
$1.2B
n/a
150
0
100
0
Jul 1979
n/a
Rexon Business Machines
5800 Uplander Way
Culver City, CA 90230
S1.5M
1978
42
2
13
2
Jul 1979
200
Smoke Signal Broadcasting
31336 Via Colinas
Westlake Village, CA 91361
n/a
1976
80
20
40
20
Feb 1980
100
Southwest Technical Products
219 W. Rhapsody
San Antonio, TX 78216
n/a
1964
125
30
125
30
Jun 1979
80
Technico, Inc.
9051 Red Branch Road
Columbia, MD 21045
$3.4M
1965
14
26
4
4
Dec 1976
6000
TEI, Inc.
5075 S. Loop East
Houston, TX 77033
n/a
1967
100
10
100
10
Dec 1979
500
Three Rivers Computer Corporation
160 N. Craig Street
Pittsburgh, PA 15213
n/a
1974
0
0
1
0
Mar 1980
30
Vector Graphic, Inc.
31364 Via Colinas
Westlake Village, CA 91361
$40 M
1976
225
50
225
50
Jan 1979
10000
Zilog, Inc.
10460 Bubb Road
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$40M
1974
5
3
9
6
Jan 1980
n/a
JUNE 1980
INTERFACE AGE 87
RODNAY ZAKS
applications
book
RODNAYZAKS J ^YBEX
6502
rv
wHh JVDCX
PROGRAMMING THE 6502
This book is designed as a progressive,
step-by-step approach to assembly lan-
guage programming-with excercises
developed to test the reader at every
step. Learn to write complete applica-
tions programs. Features: Programming
and addressing techniques, input/output
techniques and devices, application
examples, data structures, program
development and more.
Ref. C202 $12.95
CIRCLE INQUIRY NO. 64
6502 APPLICATIONS BOOK
This title presents real life application
techniques for any 6502 based micro-
computer board. Programs presented
cover building a complete home alarm
system, electronic piano, motor speed
regulator . . . and more. Learn techniques
ranging from simulated traffic control to
analog-digital conversion. The KIM-1,
SYM-1 and AIM 65 are thoroughly
covered.
Ref. D 302 $12.95
6502 GAMES
Designed as an educational text on
advanced programming techniques,
this book presents a comprehensive set
of algorithms and programming tech-
niques for common computer games. All
of the programs were developed for the
6502 at the assembly language level.
Learn how to devise strategies suitable
for the solution of complex problems
commonly found in games.
Ref. G402 $12.95
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The Teacher and
the Personal
Computer:
Alternatives in
Instruction
By Samuel W. Spero
INTRODUCTION
The instruction process whether it is taking place at the
elementary school level or in college must include four ele-
ments. These are: motivation, learning experience, reinforc-
ing experience, and evaluation. The diagram below illus-
trates the relationship between these four elements.
MOTIVATION
LEARNING f~ * REINFORCING
EXPERIENCE t r EXPERIENCE
EVALUATION
Learning Relationships
While the order in which these elements take place or
whether these elements are explicitly or implicitly addressed
can vary, in one way or another these four elements must be
accounted for in all good teaching.
The manner in which a teacher implements any or all of these
four elements is called instructional strategy. The instructional
strategy, related to the individual teacher’s personality and
style, should be clearly differentiated from the curriculum
objective. The curriculum, what the students learn, can be
stated very clearly and unambiguously, but the objective does
not have to include the manner in which it is to be learned.
Let us review briefly these four elements. A thorough
understanding of a teacher’s instructional strategies will help
clarify the particular strengths of personal computers.
If a student is not motivated, there is little a teacher can do
to help the student learn. Punishment is often used to threaten
the unmotivated students. In the short range this occasionally
works with certain groups, but in making a lasting impres-
sion this approach is not recommended. Motivation can also
be achieved by presenting the material in an interesting
and/or relevant fashion using the student’s own intrinsic
curiosity. The teacher chooses an instructional strategy
which includes motivational elements so that students will be
interested in what follows.
The actual curriculum objective is introduced in a learning
experience. The learning experience need not be a lecture,
nor is it necessarily several pages in a text. Films, labora-
tories, field trips are all possible learning experiences. The
teacher must decide which learning experience is most
appropriate for the particular objective. For example, a lec-
ture is not appropriate for learning to drive, but it might be
for learning about history.
Learning theory specialists have discovered that no matter
how impressive the learning experience, it must be reinforced
by other experiences before learning can actually take place.
This reinforcing experience is in fact the basis for homework.
For example, in a mathematics class the students watch the
teacher work out a problem in class — the learning experience
in this case is lecture and blackboard. Their reinforcing exper-
ience is to work on problems from their text, using the same
procedure employed by their teacher. The reinforcing exper-
ience uses the text and overt responses of the students. Any
learning experience can also be a reinforcing experience.
Finally, as part of the teacher’s overall instructional strategy,
there must be evaluation. By evaluation we not only refer to
grading students, but also an evaluation of the instructional
strategies themselves. The teacher must determine if the in-
structional strategies were effective. If the students learned,
was it because of, or in spite of the instruction strategy; if the
students did not learn, where did the instructional strategy
fail? Perhaps the students were not motivated or the learning
and reinforcing experiences were not appropriate. Evaluation
is important to the total instructional process.
When a teacher considers a new medium for incorporation
into his or her instructional strategies, many questions must
be asked:
Will this medium help motivate my students?
Will it provide a more meaningful learning experience?
Will it create a more relevant reinforcing experience?
Will it permit me to perform a more effective evaluation of
my students and my instructional strategies?
TEACHING WITH THE PERSONAL COMPUTER
Microcomputers are making their way into the classroom
and becoming one of the most effective instructional strate-
gies an instructor can use.
One teaching strategy uses Radio Shack’s TRS-80 to drive
a 24-inch television monitor instead of the 12-inch monitor
which is normally sold with it. Because of the graphics cap-
ability of the TRS-80, as well as its 32-character-per-line out-
put on the television screen, it is possible for all the students
to simultaneously view the computer printout on the screen.
Using this feature we have been able to develop computer-
based instructional units in which the computer — with the
television monitor— functions as a “dynamic blackboard.”
The computer is used to generate material on the television
screen which provides a framework for classroom discus-
sion. Used in this way, the personal computer has made the
conventional classroom, with its 30 or 40 students, far more
exciting and has led to improved learning, according to
teachers using this strategy.
The second instructional strategy used is the small, port-
able, high-speed printer (the Quikprinter I) available with the
TRS-80. It generates printed materials for motivation,
enrichment, reinforcement as homework assignments or
data for a learning experience. It can also be used for evalua-
tion and measurement. The materials generated by the
printer can be duplicated for the entire class by the computer
itself which prints at 180 characters per second. The com-
puter can also print individualized sets of materials for the
students where the computer prints each student’s name at
the top of their unique problem assignment. The use of the
computer to generate classroom materials has led to increased
student motivation and learning without substantially increas-
ing the work of the teacher.
JUNE 1980
INTERFACE AGE 89
At the “bottom line” of both of these instructional strate-
gies which incorporate the use of the personal computer is
their cost-effectiveness. Compared to alternative computer
hardware approaches, personal — or microprocessor based
— computer systems are the least expensive. Using these
personal computer systems, teachers are more effective at
accomplishing what they were not able to before.
HARDWARE
The hardware configuration used to implement the above
strategies includes the following:
a. the central processing unit (CPU) which is the TRS-80
Level II with 1 6K of memory. The CPU includes key-
board, DIN connectors for power supply, TV monitor,
tape recorder and a parallel-port connector.
b. the television monitor. The Radio Shack TRS-80 uses
a DIN connector to connect the television monitor to
the CPU. The DIN connector is available at any elec-
trical supply store, and the wire connections are straight-
forward and described in the Level I manual. The
TRS-80 has two different sizes of characters which can
be presented on the screen: 64-characters-per-line and
32-characters-per-line. It is this latter and the graphics
which are used in the classroom.
c. cassette tape unit for program and data storage. The
use of audio-cassette technology for program storage
makes it convenient to transfer programs between
teachers and schools. It also permits the development
of inexpensive software on a commercial basis. The
neophyte computer user, i.e. the classroom teacher,
also enjoys having complete possession of his own
program library. With audio-cassettes this is possible.
Mini-diskette systems are becoming increasingly
available also. The storage medium — the. mini-
diskette — is only slightly more expensive than the
audio cassette. The advantage of the diskette system is
the speed and reliability. However, they are also more
expensive. To add a diskette unit to the TRS-80, an
expansion interface must be added which has the port
to which the diskette unit is attached. It is also recom-
mended that 1 6K more of memory be added to the in-
terface because the disk operating system uses a con-
siderable portion of the 1 6K in the CPU.
d. the high-speed printer. The Quickprinter I, which is
Radio Shack’s version of the Centronics P-1 , prints at
180 characters per second, prints both upper and
lower case, and prints in three character sizes.
Although this printer uses special paper, a sheet about
8 Vi inches long costs no more than a penny or two.
Besides the actual hardware, there are several other
features of the TRS-80 which make it very attractive to the
classroom teacher. These are:
a. portability. The TRS-80 with all the hardware men-
tioned above can be placed in its entirety on a cart and
transported to different classrooms and schools. The
only requirement to operate the system is an electrical
outlet. Moving the computer to the students rather
than vice versa is important since moving students
from their regularly scheduled classrooms can be very
disruptive.
b. ease of service. Any Radio Shack store in the country
will accept a TRS-80 for service. They, in turn, will
send it on to a local service center for repair — their
responsibility, not yours. It may be possible to use a
“loaner” while the other system is being serviced. This
represents a tremendous convenience for teachers
who are somewhat leery of the hardware in any case.
c. low-cost. A 32K TRS-80, Level II, plus monitor,
cassette recorder, expander box, printer and mini-
diskette unit costs under $3,000. This is the cost fora
complete system. It is not necessary to have a service
contract on the hardware because Radio Shack will
repair any problems for a very nominal fee.
To estimate the “real” cost of this system to educa-
tion, consider the following exercise. If we amortize the
$3,000 over three years, assuming we use the hard-
ware ten months per year and 20 days per month, we
arrive at a figure of $5.00 per day for the hardware. If
the computer is used 5 hours per day the cost is about
$1 .00 per hour for an entire class to use the personal
computer. On a per student basis that averages out to
about $.05 per student per hour.
STRATEGY 1 - THE ‘ DYNAMIC BLACKBOARD”
The way a teacher uses a blackboard is the way a com-
puter is used in the first strategy. Generally a blackboard is
used to create a framework for classroom discussion — even
if the “discussion” is primarily the teacher lecturing. Seeing
the various salient points of the lecture in print on the black-
board helps the students understand.
Because setting up material on the blackboard can be
time-consuming and tedious for the classroom teacher, alter-
natives to the blackboard have been developed. The most
popular of these is the overhead projector. Its advantage over
the blackboard is that materials for classroom discussion can
be prepared ahead of time.
In many ways the use of the computer with a television
monitor can be compared to the overhead projector in that
the materials are prepared ahead of time. Also materials can
either be prepared professionally or by the teacher himself.
The computer has several advantages over the blackboards
and overhead projectors. One advantage is convenience.
When many overheads are to be used, there is much flipping
and sorting of transparencies. “Flipping and sorting” with
the computer are accomplished at the touch of a key. The
computer programs are stored on audio-cassettes which take
up far less room and are easier to carry than the bulky over-
head transparencies. Furthermore the presentations on the
computerized “blackboard” are dynamic. Animation and
teacher-designed graphics bring unique situations to the
“dynamic blackboard.”
Because we live in a generation of students raised on tele-
vision, the use of this medium seems to have an unexplain-
able hold on the students’ attention. Students who would
otherwise ignore the blackboard and even overhead trans-
parencies will pay close attention to the television monitor.
This is a phenomenon which crosses boundaries of subject
matter as well as level of instruction.
Mathematics
In mathematics instruction we use the random number
generator (the RND function) to generate problems which
are presented on the television screen. The students are then
asked to solve the problem in class. After a few moments
(and under the teacher’s control) the computer solves the
problem step-by-step so that students can check if the way
they solved the problem is correct. Because every step of the
computer’s output is under the control of the teacher, he is
able to discuss each of the steps in solving the problem in as
much detail as required. In other words, the computer is pro-
viding a framework for classroom discussion, just as the
blackboard would.
But now, having completed one example the teacher can
type RUN and receive another example which can be
presented in as much detail (or less) as the first example. This
process can be continued as long as the teacher feels that it is
necessary. The teacher can bypass the explanations and use
the problems generated for quizzes or for individualized
work by students having difficulty.
Language Study
The “dynamic blackboard” can be used to teach foreign
languages. For example, if Hebrew is taught, the graphics
capability of the TRS-80 generates large Hebrew characters
on the screen. The computer generates the conjugation of a
particular root form and asks the students to identify the
90 INTERFACE AGE
JUNE 1980
tense and the person. Using animation the computer re-
inforces the correct answer by circling the various prefixes
and suffixes that characterize this tense and person. A nor-
mally boring topic can be made fun using games, with two
teams competing, and as an individual or small group
tutorial. The computer is used to motivate drill-and-practice
which is the essence of language study. The implications of
this approach for study in any language including English
are fairly obvious.
Science and Social Studies
In these areas the graphics capability of the TRS-80 to
create diagrams and animate processes is used. For exam-
ple, in social studies the TRS-80 is used to draw the map of a
state (Ohio) and then quiz the students as to the location of
various cities in the state. In general science, the TRS-80
may create a pump on the screen. The pump actually moves
through its various cycles. As the basis for classroom discus-
sion both of these applications of the “dynamic blackboard”
have proven to be invaluable for motivating students and
helping them learn.
We have only begun to describe the ways the dynamic black-
board can be used. The TRS-80-based dynamic blackboard
has provided a motivational framework for instruction, in
some cases it has provided a most effective learning experi-
ence, often it has provided an excellent reinforcing experience
and a source of questions for quizzes in classroom evaluation.
STRATEGY 2 - “MATERIALS GENERATOR”
The classroom teacher spends considerable time prepar-
ing materials of one sort or another for distribution to the
class. These materials can be homework assignments, a quiz
or a test, or even something for students to work on for
enrichment or remediation. The teacher may also prepare
“fun”-type materials such as WORDFIND or CROSS-
WORD puzzles for use by the class. These serve to motivate
students to undertake a reinforcing experience. To prepare
such materials, the classroom teacher must first locate such
materials, then transfer them to a medium appropriate for
duplication. This process is of such importance to the class-
room teacher that an entire extra-textbook materials industry
has evolved selling such materials to teachers.
The TRS-80 with the Quickprinter can be used as a highly
effective materials generator which is more cost-effective and
more flexible than the materials that can be purchased in the
teacher stores. While the idea of using the computer to gen-
erate classroom materials is not new, the “wrinkle” that is
added to this strategy with the advent of the personal com-
puter is convenience and accessability.
Mathematics
One of the ways in which we use the “materials generator”
is to generate different problem sets for each student. The
same time the computer generates the problem set for the
student, it generates the solution for the teacher. One exam-
ple is the output from such an application in the area of poly-
nomial equations in intermediate algebra.
Sample of output #1
THE POLYNOMIAL FOR
SRM SPERO
IS
2 2
X + -15. -01 X + 58. 2358 X + -18. 5867
THE PHVSlCtflflS
miCRDCDfTIPUTER REPORT
Interesting Articles on
Microcomputer
Applications in:
• Medical Account Records
• Tax Record Preparation
• Automated Patient Billing
• Patient History Review
• Drug Inventory and
Prescription Printing
• Employee Compensation
• Disease and Drug Cross-
Indexing
• Success of Treatment
Evaluation
• Lab Data Processing
• Access to Large Medical
Data Bases (Toxicology)
• Third Party Billing
• Patient Scheduling
• Word Processing
• Continuing Medical
Education
• Aids for the Handicapped
• Microcomputer Book
Reviews
• Bio-Med Statistics
• MUMPS on Micros
• Investment Analysis
• Computer Games
CIRCLE INQUIRY NO. 53
The information contained in the Physicians Micro-
computer Report could save you thousands of dollars
and a lot of headaches.
The burgeoning costs of health care can only be
controlled by the most efficient means of data ac-
quisition, recording, and processing.
There is no doubt that microcomputer technology
will touch every phase of medical practice.
In the Physicians Microcomputer Report you
get objective analysis on:
• How to pick the microcomputer system that best
suits your medical and professional needs.
• Where to find low cost medical and business
software.
• Articles and programs written by physicians on
microcomputer application in business, research,
and their own specialties.
• News on the latest developments in medical
electronics and microcomputer applications.
• Articles for the novice medical microcomputer
user.
• National coordination of microcomputer medical
software development and coverage of medical
related computer conferences.
• No nonsense economic facts on whether now is
the time for you to computerize or just add more
personnel.
• Analysis of the future impact microcomputers will
have on the allied medical areas.
Please start my Club Membership and Subscription to the Physicians Microcomputer Report.
A limited number of free sample copies are available if you hurry.
Name (Print)
City
Address
State
□ $25 One year (12 issues)
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Sand to:
Dr. Garald M. Orouz, Editor, Physicians Microcomputer Report,
Box 6483, Lawrancavilla, N.J. 06648
THE P0LYN0M2RL FOR
SRM SPERO
IS
3 2
X + -15. 01 X + 58. 2358 X + -18. 5867
THE ROOTS ARE
. 35 6. 54 a 12
THE EXTREME? ARE
FOR X = 2. 63238 V = 48. 9423
FOR X = 7. 37429 V = -4. 37031
The “materials generator’’ is also used to provide materials
for several games such as MATHAGRAM and MATH-BINGO.
Language Study
The special types of materials which teachers prefer to pre-
pare in language study lie primarily in the area of language
games. The TRS-80 is especially strong in manipulating
“strings.” One of the popular games used extensively (and
not only in language study) is WORDFIND puzzles. The
teacher supplies a vocabulary list and within moments the
computer generates a WORDFIND puzzle for use by the class.
Sample of output #2
mm mm is the m mm
2ED NlffiER IS W ffiM HMR
3RD mm IS THE DIRECTION UMBER
i = m
2= RIGHT
3 = R- UP 4 = nm
5 = UP
6 = LEFT
7 - L-MRW § =
l-up
ii? i
m
115 1
aimo
28 8 2
DELHME
11 1 3
ILLINOIS
612 4
mm
1811 4
KENTUCKY
3 3 2
mm
12 5 1
OHIO
1814 2
im
311 1
vmm
2
S
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==:
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28
Another popular game approach used in language courses
is the computerized MADLIB approach. We cannot show
the entire dialogue that gives rise to the following, but we are
able to generate uniquely tailored materials for each student
using information supplied by the student as in Roger Price’s
original Madlibs.
Sample of output #3
HEERE IS THE STORV rUK
S F-f M S F> E R O
mi upon ft time m spend m kit mm
MISSED THE HISS ISSIPPI RIVER ® THEIR M 70 CALIFORNIA
mm mum herds if rattlesnakes
m SAM BLUE PAINTED IDIfiNS OF THE fPfm TRIE
MMf MRS AFRAID fiND RfiN fiNHV FROM OREGON
SDR STfi® AND m KILLED BY CHIEF CRffir HORSE
GfN you FID ftT LESS! M3 ERROFS IN SPERO’S STORV?
PROVE THE' ERRORS 8V US OF VOIR TEXTBOOK.
Science and Social Studies
In science and social studies, the computer is used to generate
realistic data which can be analyzed by the students in order to
apply procedures being studied, as well as to learn about various
phenomena. For example, the famous Huntington II simula-
tion packages have been adapted to use with the TRS-80.
One of the simulations is the Millikan Oil Drop Experiment
for determining the ratio of electric charge to the mass of the
electron. The computer generates the actual data to be obtained
from the experiment which the students can then analyze.
The learning experience using the computer simulation is as
good as that obtained in the laboratory experiment. By not
having to do this experiment in the physics laboratory, the
students have time to perform those experiments which lend
themselves more to the actual lab experience.
CONCLUSION
The two instructional strategies place the computer into an
instructional role for which it is well-suited. In this role it pro-
vides the classroom teacher with technological assistance in
completing tasks which the teacher cannot or will not per-
form himself. To provide this assistance, only a minimal
computer facility is required -*■ a so-called personal com-
puter — which is relatively inexpensive. The teacher who
uses the computer either as a “dynamic blackboard” or as a
“materials generator” reaps maximum benefit. □
92 INTERFACE ACE
JUNE 1980
MicroQuote
Your personal computer becomes
a window on Wall Street.
MicroNET, the personal computer service of
CompuServe, now offers MicroQuote, a compre-
hensive securities information system.
With MicroQuote you can gain information from
a data bank of over 32,000 stocks, bonds and op-
tions from the New York, American, OTC and major
regional markets plus Chicago options. MicroQuote
contains price and volume data from January, 1974
with cumulative adjustment factors and dividend
information from January, 1968.
You can determine indicated annual dividends,
earnings per share, shares outstanding, BETA fac-
tors, open interest on options and amount outstand-
ing on debt issues. MicroQuote can provide issue
histories on a daily, weekly or monthly basis and
even performs certain statistical analyses on the
data. It’s a vital tool for any investor.
It’s just part of the MicroNET service
MicroNET also allows error-free downloading of
software via the new software exchange and execu-
tive programs (now available for the TRS-80, R Apple
II” and CP/M R systems). It also provides electronic
mail service and can be accessed with a 300 baud
modem via local phone calls in more than 175 U.S.
cities. Write for full details on how your microcom-
puter can control one of the nation’s largest and
most sophisticated time-sharing computer centers
for about 8 cents a minute!
TRS-80 is a registered trademark of Tandy Corporation
Apple II is a registered trademark of Apple Computer. Inc.
CP/M is a registered trademark of Digital Research
Regional distributors and local dealers wanted.
Inquire to Dept. R
Software authors: MicroNET seeks to license quality
programs for software exchange. Write to
Dept. S
~ n/tu */ 'iiixiii SSL
Mail to: Dept: I
rnmnilClDrVD Personal Computing Division
VC 5000 Arlington Centre Blvd.
Columbus, Ohio 43220
JUNE 1980
CIRCLE INQUIRY NO. 10
INTERFACE AGE 93
My TRS-80 Likes Me
When I Teach Kids
How to Use It '
Part 10
By Bob Albrecht
Copyright 1 980 by Bob Albrecht
WANDERING STAR, AGAIN
Last time we introduced you to Wandering Star, who
wanders about the screen eating cosmic dust. Wandering
Star first appears near the center of the screen, then rests for
a brief time, perhaps thinking hungrily about cosmic dust.
After her brief rest, Wandering Star wanders. . .up, down,
left, right. . .on the screen. If she should meander into a
place that contains a cosmic dust mote, she eats it, and
moves on.
Eventually, Wandering Star may reach the edge of the
screen and disappear. This usually happens long before she
has consumed all available cosmic dust.
If you tried our Wandering Star program, perhaps you
notice that occasionally she wanders in a very strange way.
Sometimes she jumps all the way from the left edge of the
screen to the right edge, or from the right edge to the left
edge. This happens, for example, if she is poised right at the
edge of the screen at position 255 and tries to wander one
place to the right to position 256. Position 256 is on the left
edge of the screen, one line down from the line that includes
position 255.
So we bring to you a new Wandering Star program, in
which she wanders in a more mundane way without the
benefit of hyperspace jumps.
100 REM*** WANDERING STAR #2
110 CLS
200 REM* **COSMIC DUST
210 FOR K = 1 TO 200
220 PRINT @ RND(1 022),
230 NEXT K
300 REM* **WANDERING STAR APPEARS
310 ROW = 7
320 COL = 32
330 PRINT @(64*ROW + COL), “*”;
400 REM* * *WANDERING STAR RESTS
410 T = 2000
420 FOR Z = 1 TO T : NEXT Z
500 REM* **WANDERING STAR WANDERS
510 PRINT @(64* ROW + COL), “ ” ; She leaves her old
520 W = RND(4) place
530 IF W = 1 THEN ROW = ROW + 1 She might go down
540 IF W = 2 THEN ROW = ROW - 1 She might go up
550 IF W = 3 THEN COL = COL + 1 She might go right
560 IF W = 4 THEN COL = COL - 1 She might go left
600 REM* **DID SHE GO OFF-SCREEN?
610 IF ROW <0 OR ROW > 15 THEN 910
620 IF COL < 0 OR COL > 63 THEN 910
630 IF 64* ROW + COL = 1023 THEN 910
700 REM***NO, SHE IS STILL ON-SCREEN
710 PRINT @(64*ROW + COL), “*” ;
720 T = 100
730 FOR Z = 1 TO T : NEXT Z
740 GOTO 510
900 REM * * * WANDERING STAR GOES OFF-SCREEN
910 PRINT @ ), “WANDERING STAR HAS LEFT THIS
UNIVERSE.”
920 PRINT “FAREWELL, WANDERING STAR.”
930 GOTO 930
Compare this program with our first Wandering Star program
in the April 1980 issue of INTERFACE AGE. Last time, we
thought of the screen as having 1024 print positions num-
bered from 0 to 1023. We avoided position 1023 because,
if you print something there, everything on the screen scrolls
up one line. Also see line 630 of our new program.
This time, we think of the screen as having 1 6 rows with
64 columns in each row. The rows are numbered from 0
(top row) to 15 (bottom row); the columns are numbered
from 0 (left edge) to 63 (right edge).
1 6 rows x 64 columns = 1 024 screen positions
In lines 330, 560 and 720, something is printed at a
screen position in row ROW and column COL. For example,
330 PRINT @ 64* ROW + COL, “*”;
In lines 510 through 560, Wandering Star wanders. First,
she leaves the place where she was (line 510). Then she de-
cides whether she will move down (W = 1 ), or up (W = 2), or
right (W = 3), or left (W = 4).
She just might wander off-screen. This is checked by lines
610 and 620. If she wanders off-screen, the program jumps
to line 910 and prints an appropriate message. This also
happens if she wanders into position 1 023 (line 630). Why?
Because printing something in position 1023 causes
everything on the screen to scroll up one line.
However, if she has stayed in the tiny universe of the
TRS-80 screen, we must show her at her new place. This is
done in lines 7 1 0 and 720. Finally, line 730 sends the com-
puter back to let Wandering Star wander again.
THE RETURN OF WANDERING STAR
Well, Wandering Star wanders and. . .eventually. . .
wanders off the screen, never again to appear on-screen.
Farewell, Wandering Star.
Alas, the part of the universe surrounding the screen is a
cosmic desert. The screen, of course, is a cosmic oasis.
So, after wandering in the desert for awhile, Wandering
Star decides to return to the oasis where she can again savor
cosmic dust and think about other oases elsewhere in the
universe (and therein lies another story).
Think about how Wandering Star might return. She left the
universe along one of the edges of the screen. . .Hmmm, per-
haps she could reappear somewhere at the edge of the screen.
Does she learn from experience? Will she soon disappear
again into the desert? Or will she remain in the food-rich
oasis, pondering upon the greater universe, then invent or
discover a way to move beyond the cosmic desert into other
(and different) oases?
94 INTERFACE AGE
JUNE 1980
SELECTED SHORT SUBJECTS*
We call the following program “Countdown-Blastoff!”
Enter it into your TRS-80 and RUN it.
100 REM* * *COUNTDOWN-BLASTOFF!
110 CLS
200 REM* * *COUNTDOWN FROM 10 TOO
210 FORC = 10 TOO STEP -1
220 PRINT C
230 FOR Z = 1 TO 300 : NEXT Z
240 NEXT C
250 PRINT “BLASTOFF!!!” : T = 400 : GOSUB 910
300 REM* * *SHOW SPACESHIP ON LAUNCH PAD
310 CLS
320 PRINT @512, “
330 PRINT “ *U* ”
340 PRINT “ *S* ”
350 PRINT “ *A* ”
360 PRINT “ ***** ”
370 PRINT “*******”
380 T = 400 : GOSUB 910
400 REM***LAUNCH THE SPACESHIP
410 PRINT “ !!! ” : T = 300 : GOSUB 910
420 PRINT “ !!! ” : T = 200 : GOSUB 910
430 PRINT “ !!! ” : T = 100 : GOSUB 910
440 FOR K = 1 TO 16
450 PRINT : T = 100 : GOSUB 910
460 NEXT K
500 REM * * * ANNOUNCE A SUCCESSFUL LAUNCH
AND STOP
510 CLS
520 PRINT “ALL SYSTEMS ARE GO. EVERYTHING IS
AOK!”
530 END
900 REM ***TIME DELAY SUBROUTINE
910 FORZ = 1 TOT: NEXT Z
920 RETURN
Now that you are launched into space, play our simple re-
action time game to pass time until you reach your destination.
100 REM* **REACTION TIME PROGRAM
200 REM * * * INSTRUCTIONS TO THE PLAYER
210 CLS
220 PRINT “HOW FAST ARE YOU? I WILL CLEAR THE
230 PRINT “SCREEN FOR A LITTLE WHILE, THEN
240 PRINT “COUNT NEAR THE MIDDLE OF THE
250 PRINT “SCREEN. WHEN I START COUNTING,
260 PRINT “PRESS THE SPACE BAR AND I WILL
261 PRINT “STOP. STOP ME QUICKLY, IF YOU CAN!”
262 PRINT : PRINT “WHEN YOU ARE READY, PRESS
263 PRINT “ANY KEY”
270 IF INKEY$ = “” THEN 270
300 REM* * *CLEAR THE SCREEN FOR A RANDOM
TIME, T
310 CLS
320 T = RND (2000)
330 FOR Z = 1 TO T : NEXT Z
400 REM * * * START COUNTING, SPACE BAR STOPS IT
410 X = 1
420 PRINT @472, X
430 IF INKEY<>“ ” THEN X = X + 1 : GOTO 420
500 REM*** PLAYER PRESSED SPACE BAR. PAUSE,
THEN PLAY AGAIN.
510 T = 2000
520 FOR Z = 1 TO T : NEXT Z
530 GOTO 210
*This section is excerpted from the book TRS-80 BASIC: A Self-Teaching
Guide by Bob Albrecht, Don Inman and Ramon Zamora, copyright 1980
by John Wiley and Sons, Inc.
Play several times. An average of 10 is fast; congratula-
tions. If your average is more than 20, well. . .maybe you are
thinking about something else.
Humm. . .we played the game several times and discov-
ered a way to cheat. We can stop the computer with a count
of 1 every time. We can do this, not because we are that fast,
but because there is a flaw in the program.
Beat the computer. Figure out how to stop the computer at 1
every time just by pressing the space bar. Later we will share
our discovery with you, then show you how to fix the “bug” in
the program so that this kind of cheating can’t happen.
IMPORTANT. This computer error is not the fault of the
computer. Rather, as are almost all computer errors, it is the
fault of the programmer. This error almost escaped our
notice. Imagine the letters we might have received if we had
missed it.
COMPUTERTOWN, USA
This series is for teachers, parents or others who wish to
help kids learn to use, program and enjoy computers. In
ComputerTown, USA, kids do this in the public library.
We have found some especially good stuff to recommend
to you.
Robert Purser's Magazine
P.O. Box 466, El Dorado, CA 95623
The most complete source of information about commer-
cially available software for the TRS-80, Apple computers.
Quarterly, $ 12/year.
CLOAD Magazine
Box 1267, Goleta, CA 93017
The best software bargain we know of for people who wish
to help kids learn. This is a cassette magazine; each month
you get a cassette with several programs to plug into your
TRS-80. On a scale of one to ten dragonsmiles, CLOAD
gets ten dragonsmiles. $36/year.
Adventure International
Box 3435, Longwood, FL 32750
The Adventure games from this company are one of the
best ways we know for a child to learn and love problem-
solving.
Cybernautics
Box 40132, San Francisco, CA 94140
Their games, TAIPAN and GALACTIC EMPIRE, are the
best simulation games we have seen for a 16K TRS-80.
Try ’em — you will never go back to Hammurabi, King-
dom, Star Trek, etc.
The Software Exchange
6 South St., Box 68, Milford, NH 03055
Perhaps the most complete source of cassette and disk
software, books and magazines for your TRS-80. Ask for
its catalog.
Computer Information Exchange
Box 158, San Luis Rey, CA 92068
CIE publishes a newspaper called S-80 Bulletin, S-80
Computing Magazine and People's Software — inexpen-
sive cassettes with lots of programs.
And, as usual, for more info on ComputerTown, USA send a
stamped, self-addressed envelope to ComputerTown, USA,
P.O. Box 310, Menlo Park, CA 94025.D
Copies of “My TRS-80 Likes Me, " Parts One and Two
are now available free from Radio Shack. Interested persons
should write to Sharon Ross, Radio Shack Circulation Dept.
3, 1300 One Tandy Center, Fort Worth, TX 76102.
Bob Albrecht can be contacted at P.O. Box 310, Menlo
Park, CA 94025.
JUNE 1980
INTERFACE AGE 95
TRS-80 MOD II
WORD PROCESSING
dUPDciisy
WORD PROCESSOR
The best is now even better...
New Features
New Commands
New Capabilities
New Manual
SPECIAL PACKAGE INCLUDES:
• Wp Daisy™ word processor
• Mail Merge™ mailing list package
• I/OS operating system
full CP/M™ & CDOS
compatability
Includes
— Diablo, Spinwriter and
Qume support
— Printer spooling
— 30 programs
CP/M™
TM of Digital Research
CIRCLE INQUIRY NO. 35
Reliable Business
Bookkeeping
Software
ORDER ENTRY
MICROSOFT CP/M r , PET,
APPLE II, MICROPOLIS:
$350/ea.
GL, A/P, A/R,
INVENTORY,
PAYROLL
Buy simple, effective
programs designed
specifically for your
machine. Call us once
for same week delivery
on a product you can
use the day you
receive it, and two
years from now when
your company is twice
TRS-80 MOD I: $100/ea.
CBASIC-CP/M r : $200/ea.
ATARI, PET, APPLE II,
TRS-80 MOD II,
MICROPOLIS,
VECTOR, EXIDY,
DYNABYTE, CROMEMCO,
MICROSOFT CP/M r :
$140/ea.
They all work together!
as big.
Order today by U P S.
COD. We'll pay
postage and handling
on Am. Ex., Visa,
Mastercharge, or pre-
paid orders.
467 HAMILTON AVE. PALO ALTO, CA. 94301
CIRCLE INQUIRY NO. 9
MATHTEST
By Bethany Prendergast
Microcomputers are particularly well adapted for use by
the elementary school teacher. Their various uses in the role
of C.A.I. (Computer Assisted Instruction) have been well
documented by teachers and manufacturers alike. There is,
however, another role for the microcomputer in the class-
room that is passed over most probably because it lacks the
glamor of the more exotic uses.
This role uses the microcomputer to relieve the teacher
from the time-consuming administrative duties involved in
the classroom. Nowhere is the need for this more evident
than in the elementary math classes. The good teacher is
faced with the monumental task of planning, writing, giving
and correcting workpapers and tests.
This program is not just intended for teachers, however. It can
very easily be used by parents who are concerned about their
children’s math. There are many times when parents want to
drill their children in math fundamentals, but found either
writing the tests or correcting them to be tedious work.
The need for the MATHTEST program came to me dur-
ing this last year while I was introducing a course on micro-
computing to the 7th and 8th graders at Assumption School
in Jacksonville, Florida. The idea is to provide the teacher
with a means to produce tests/workpapers almost at will.
Each one can be made different, so there is no need to worry
about cheating. The program is written for the TRS-80 Level
II, but will operate on any 4K + machine with very little
modification. Just type it in and follow the prompt questions
as they appear on the screen. There are remark lines
throughout that explain what’s happening.
The program is designed to generate any number of multipli-
cation, division, addition or subtraction test papers with up to
20 problems per page. It allows for 0-3 decimal places for the
x and y, which are randomly selected numbers. The answers
can either be placed on the same paper with the problems, or
can be on a separate page. The answers that are generated
will be to 4-place accuracy because of the print using state-
ment. For more accuracy, that would have to be altered.
When the program is run, the user answers the prompt on
the screen to determine the number of tests, the number of
problems per page, the number of decimal places the x and
y will have, and whether the test is to be multiplication, divi-
sion, addition or subtraction. □
Program follows
96 INTERFACE ACE
JUNE 1980
PROGRAM LISTING
10
20
30
40
50
60
7 -PROGRAM LISTING FOR PUBLICATION - 08/01/79
'-PROGRAM NAME IS MATHTEST BY BETHANY PRENBERGAST
' -904/642-1902 * WRITTEN FOR THE TRS-80 LEVEL II WITH LINE
'-PRINTER OF 30 COLUMNS. PROGRAM WILL GENERATE RANDOM TESTS
'-IN ACCORDANCE WITH ENTRIES FROM PROGRAM PROMPTS.
'-SET PP AHEAD OF P TO PREVENT DIV.BY 0 LATER
70 BEFDBL A* X, Y
80 CLSI RANDOM ;PRINT"MATH PROBLEMS"
70 INPUT"ENTER NO. OF DECIMAL PLACE3( 0, 1 ,2,3 )" ,‘P
100 INPUT "NO. OF DIFFERENT TESTS DESIRED" 5S
110 INPUT" ENTER NO. OF COPIES OF EACH TEST" »TD
120 INPUT" ENTER TEST TYPE - ( ADD, SUBT, MULT »BIV )",*MD$
130 IF MD$<>" MULT" AND MD$<>"DIV" AND MB$<>" ADD” AND MD$<>"SUBT" THEN 120
140 IF P=0 THEN PP=1
150 IF P=1 THEN PP=10
160 IF P=2 THEN PP=100
170 IF P=3 THEN PP = 1000
180 INPUT H ENTER NO. OF PROBLEMS DESIRED ON EACH TEST PAPER" 5T
190 DIM X(S,T>, Y(S,T), A(S,T>
200 INPUT" ENTER MAX. VALUE FOR X (WHEN X/Y,X*Y >" ,‘L1
210 INPUT "ENTER MAX. VALUE FOR Y (WHEN X/Y,X*Y)"5L2
220 'STORE PROBLEMS IN R.A.M.
230 CLSt PRINT"WORKING"
240 FOR II = 1 TO S
250 FOR I = 1 TO T
260 X< 1 1 , 1 )=RND( LI ) I Y( 1 1 , 1 )=RND( L2 )
270 IF Y( II, I )>X( 1 1 ? I > THEN260
230 IF XdI,I)=0 OR Y( II»I )=0 THEN 260
290 '-RANDOMLY SELECT X, Y OR BOTH X AND Y TO CONTAIN DEC.FRAC.
300 CH=RNB( 9 )
310 IFCH>3ANDCH<7THENY( II,I >=Y( II, I )/PPELSEX( lit I >=X( II, I )/PPt Y( II, I )=Y( II, I )/PP
320 X< lit I )=« X< II , I )*1000 >/1000 S Y< II, I )=( Y< II, I )*1000 )/1000
330 NEXT I
340 NEXT II
350 '-PRINT OUT TEST PAPERS AND STORE ANSWERS FOR LATER
360 IF MD$="MULT” THEN 400
370 IF MD$="BIV" THEN 580
380 IF MD$=" ADD" THEN 980
390 IF MD$="SUBT" THEN 1180
400 FOR II = 1 TO S
410 FOR CC = 1 TO TD
420 LPRINT"
430 LPRINT"
440 LPRINTILPRINT
450 LPRINT"
460 LPRINTILPRINT
470 FOR I = 1 TO T
480 LPRINT" *>I»" )"»X( II, I )? "x" 5Y( II, I >,*" = "
490 '-CALCULATE ANSWER AND STORE UNDER A(II,I>
500 A( II , I )=( X( II , I )*Y( II, I ) )
510 LPRINT
520 NEXT I
530 LS = 60 - <<T*2>+7)
540 FOR ZZ= 1 TQ LS l LPRINT : NEXT ZZ
550 FOR ZZ= 1 TO 2000: NEXT ZZ
560 NEXT CC:NEXT II
570 GOTO 750
580 FOR II = 1 TO S
590 FOR CC= 1 TO TD
600 LPRINT"
610 LPRINT"
620 LPRINTILPRINT
630 LPRINT" DIVISION PROBLEMS -
640 LPRINT ILPRINT
650 FGR 1= 1 TO T
660 LPRINT" ”,‘I r )"5X< II , I ),*"/" ,*Y( II, I ),*" = "
670 '-COMPUTE ANSWER AND STORE UNDER A(II,I)
680 A( 1 1 » I )=( X( 1 1 , 1 )/Y( 1 1 , 1 ) )
690 LPRINT
700 NEXT I
710 LS = 60 - <(T*2)+7>
720 FOR ZZ = 1 TO LS : LPRINT t NEXT ZZ
730 FOR ZZ = 1 TO 2000 : NEXT ZZ
7*0 NEXT CCtNEXT II
75C IF MD$="MULT" THEN LPRINT" ANSWERS TO MULTIPLICATION TESTS"
760 IF MD*="BIV" THEN LPRINT" ANSWERS TO DIVISION TESTS"
770 IF MD$="ADD” THEN LPRINT" ANSWERS TG ADDITION TESTS"
780 IF MD$="SUBT" THEN LPRINT" ANSWERS TO SUBTRACTION TESTS"
790 LPRINT
name:"
DATE!"
MULTIPLICATION PROBLEMS
TEST PAPER * "5 II
name:
date:
TEST PAPER * HI I
800 ' -A$ AND C$ ARE USED TO KEEP ANSWERS IN COLUMNS
310 A*="
820 C$="
330 B$=' #,***,**#.**«"
840 FOR 11= 1 TO S: LPRINT" TEST PAPER # "5 II
850 LPRINT
860 '-KEEP CHECKING THAT THERE IS AN A TO PRINT
370 FOR 1= 1 TG T STEP 3
880 IF I<10 THEN X$=A* ELSE X$=C$
890 LPRINT X$,*IJ"}"»USINGB$;A(II,I>»*
900 IF I = T THEN 960
910 IF 141 <10 THEN X$=A$ ELSE X$=C*
920 LPRINT ‘USINGS*, *A(II,(IM))f
930 IF HI =T THEN 960
940 LFRINT X* ? 1+2, " )" ,*USINGB*?A( II, ( 1+2 ) )
950 IF H2<10 THEN X$=A$ ELSE X$=C$
960 next i:lprint:lprint:next II
970 END
980 FGR II=i TO S
990 FOR CC=1 TO TD
1000 LPRINT TAB(45)"NAME:"
1010 LPRINT TAB(45)"DATE:"
1020 LPRINT ILPRINT
1030 LPRINTTAB( 20 )"ADDITION PROBLEMS-TEST PAPER ♦"HI
1040 LPRINTILPRINT
1050 FOR 1=1 TO T
1060 LPRINT" •?If*)"X(II,I)5 H +"JY( 11,1)5"="
1070 'COMPUTE ANSWER AND STORE UNDER Ad I, I)
1080 A( 1 1 , 1 )=X( II, I )+Y( 1 1 , 1 )
1090 LPRINT
1100 NEXT I
1110 ' GENERATE LINE FEEDS FOR NEXT FORM
1120 LS=60-((T»2)+7)
1130 FOR ZZ=1 TO LS ILPRINT! NEXT ZZ
1140 'GENERATE FALSE LOOP BETWEEN PRINTS
1150 FOR ZZ=1 TQ 2000 INEXTZZ
1160 NEXT CCI NEXT II
1170 GOTO750
1180 FOR 11=1 TO S
1190 FOR CC=1 TO TD
1200 LPRINT TAB(45)"NAME:"
1210 LPRINT TAB(45)"DATE: K
1220 LPRINTILPRINT
1230 LPRINTTAB< 20 )"SUBTRACTION PROBLEMS-TEST PAPER *"ill
1240 LPRINTILPRINT
1250 FOR 1=1 TO T
1260 LPRINT" "il,*" )"X( II, I ), "-"fY( II, I )?" = "
1270 'COMPUTE ANSWER AND STORE UNDER A(II, I)
1280 A( II, I )=X( II, I )-Y( II, I )
1290 LPRINT
1300 NEXT I
1310 ' GENERATE LINE FEEDS FOR NEXT FORM
1320 LS=60-((T*2)+7>
1330 FOR ZZ=1 TO LSILPRINTINEXT ZZ
1340 'GENERATE FALSE LOOP BETWEEN PRINTS
1350 FOR ZZ=1 TO 2000 INEXTZZ
1360 NEXT CCI NEXT II
1370 GOT0750
JUNE 1980
INTERFACE ACE 97
Using and Building
Micro-Based Systems
Chapter Six
By David Marca, Associate Editor
This chapter develops the concept of software tools and
provides some useful examples in FORTRAN. The reader
will find an orderly progression from simple concepts to
complex examples. The organization of the article allows for
the reading and programming of independent tools that are
used in a building-block manner (one on top of the other) to
create useful applications.
FOUNDATIONS FOR SOFTWARE TOOLS
Building a foundation for developing software tools is an
important step towards well-engineered application software.
While tools can be built for any type of application area (like
the FORTRAN scientific subroutine library), the concentra-
tion here will be on non-numeric computation. This empha-
sis on character-oriented problems was taken because many
day-to-day business applications require non-numeric pro-
cessing, and also because character-oriented problems can
be understood with little application experience.
In order to build software tools, we will rely and expand
upon the concepts covered in previous articles. Basic data
concepts in FORTRAN will be enhanced by adding facilities
to define and manipulate character strings. Basic structure
concepts will be utilized to build more complex data struc-
tures. Previous algorithm concepts, including Alias/Alibi,
will be reinvestigated in the new context of character-oriented
problems. (A review of chapter five at this time may help to
firm up fundamentals of computer programs.)
While underlying concepts may be difficult, the tools
approach is rather simple — one builds upon the work of
others. Not everyone’s past work can be reused, however.
Traditionally, a program or a subroutine is constructed to
perform one or (at best) a few specific jobs. A software tool,
however, must be able to work in a multitude of different en-
vironments. It should have well-defined, simple, and stan-
dard interfaces, and avoid the idiosyncrasies of FORTRAN,
concealing the evident ones in select modules.
Lastly, but most importantly, the program or subroutine
should perform a very specific (at best, a single) function on
a small set of data. Ideally, this type of software has a well-
chosen set of filters that becomes a set of building blocks
which can be used separately or together, handling many
programming needs.
These blocks improve the quality of application software in
a micro environment. Smaller programs and subroutines de-
crease the potential for errors in testing and during actual
use. Also, limitations in programming languages and hardware
can be hidden from most of the application by the use of filters.
For example, the isolation of all I/O details in a set of sub-
routines requires changes to only those subroutines when the
software is moved to a different hardware configuration.
Good tools are also important when creating a micro-based
software system. Current micro-environments are sorely
lacking in adequate tools to produce well-engineered soft-
ware. Four such programming aids are:
• Trace facility
• File comparator
• Call and called by maps
• Documentation extraction from source code
After our software tool foundations have been established,
the above types of programming aids should be easy to im-
plement on most microcomputers having a FORTRAN com-
piler. Since there is a heavy emphasis on non-numeric pro-
cessing, we must now investigate how the FORTRAN lan-
guage handles character strings.
98 INTERFACE AGE
JUNE 1980
FORTRAN CHARACTER STRINGS
These capabilities were added to the original FORTRAN II
language in March 1966 when the FORTRAN IV standards
were approved. Hollerith constants (alphanumeric characters
surrounded by single quotes) were allowed to be used in very
limited contexts. Each numeric data type was allowed to con-
tain character information. The maximum number of charac-
ters held by a data type depended upon the hardware’s byte
length and storage allocation rules of the compiler. A rule of
thumb is one character per byte size of the data type (figure 1 ).
VARIABLE TYPE
SIZE (BYTES)
MAXIMUM CHARACTERS
ALLOWED
DOUBLE PRECISION
8
8
REAL
4
4
INTEGER
2
2
LOGICAL
1
1
Figure 1. Character capacity of Fortran data types
(for TRS-80).
Within a data type, characters can be packed using dif-
ferent formats. The programmer is allowed to read in a write-
out character using the “A” format code. One to eight
characters can be transferred to or from a variable by specify-
ing A1 to A8 respectively in a FORMAT statement (figure 2).
During input from a device, the characters are right justified
in the variable (right-most character is put in the right-most
byte, etc.).
00100
INTEGER TTY, KEY
00200
LOGICfiL CHRR1
00300
INTEGER CHAR2
00400
RERL CHAR3, CHAR4
00500
DOUBLE PRECISION CHARS, CHRR6, CHAR7, CHRR8
00600
DfiTR TTY/1/, KEY/1/
00700
WRITE (TTY, 50 >
00800
50
FORMATdH , "START OF PROGRAM")
00900
READ (KEY, 100) CHRR1
01000
100
FORMAT (1R1)
01100
READ (KEY, 200 > CHAR2
01200
200
FORMAT (1R2)
01300
READ (KEY, 300) CHRR3
01400
:<00
FORMAT (1R3)
01500
READ (KEY, 400) CHAR4
01600
400
FORMAT (1A4)
01700
READ (KEY, 500) CHARS
01.800
500
FORMAT (1A5)
01900
READ (KEY, 600) CHAR6
02000
600
FORMAT <1R6>
02100
READ (KEY, 700) CHAR7
02200
700
FORMAT (1A7)
02300
READ (KEY, 800) CHARS
02400
800
FORMAT (1A8)
02500
WRITE (TTY, 9999)
02600
9999
FORMAT (1H , "END OF PROGRAM' )
02700
STOP
02:800
END
Figure 2. Reading in characters.
Characters are also allowed to be put into a variable by the
DATA statement. The programmer can specify a Hollerith
constant with a size equal to or less than the character capac-
ity of the variable. On some compilers, the DATA statement
left-justifies characters in the variable. This has been a con-
stant source of programmer errors. Try out the program in
figure 3 to see if the DATA statement right or left justifies on
your compiler.
00100
INTEGER TTY, KEY
00200
INTEGER I NIT, INPUT
00300
DATA TTV/1/, KEY/1/
00400
DATR INIT/"A"/
00500
WRITE (TTY, 100)
00600
100
FORMAT (1H , "START OF PROGRAM')
00700
WRITE (TTY, 200)
00800
200
FORMAT (1H , "PLEASE ENTER THE LETTER A - ")
00900
READ (KEY, 300) INPUT
01000
300
FORMAT (1A1)
01100
WRITE (TTY, 400) INIT, INPUT
01200
400
FORMAT (1H , "INIT=",1A1, " INPUT=",1A1)
01300
IF (. NOT. (INPUT . EQ. INIT)) GOTO 600
01400
WRITE(TTY, 500)
01500
500
FORMAT (1H , 'DATA STATEMENT RIGHT- JUSTIFIES" )
01600
GOTO 800
01700
600
CONTINUE
01800
WRITE (TTY, 700)
01900
700
FORMAT (1H , "DATA STATEMENT LEFT-JUSTIFIES")
02:000
800
CONTINUE
02100
WRITE (TTY, 9999)
02200
9999
FORMAT (1H , "END OF PROGRAM")
02300
STOP
02400
END
Figure 3.
Packing of characters— data statement vs.
read statement.
00100
INTEGER TTY, KEY, PTR
00200
INTEGER BLANK, CHAR
00 j>00
DATA TTY/1/, KEV/1/, PTR/2/, BLANK/8224/
00400
C
00500
WRITE (TTY, 100)
00600
100
FORMAT (1H , "START OF PROGRAM")
00700
WRITE(PTR, 200)
00800
200
FORMAT (1H , " ')
00900
WRITE (PTR, 300)
01000
300
FORMAT ( 1H , " CHARACTER CODE ( 1 A1 ) " )
01100
WRITE (PTR, 200)
01200
C:
01300
WRITE (TTY, 400)
01400
400
FORMATdH , "?")
01500
RE AD (KEY, 500) CHAR
01600
500
FORMAT dAl)
01700
c.
01800
600
IF (CHAR . EQ. BLANK) GOTO 800
01900
WRITE (PTR, 700) CHAR, CHAR
02000
700
FORMATdH , 4X, 1A1, 8X, 16)
02100
WRITE (TTY, 400)
02200
READ (KEY, 500) CHAR
02300
GOTO 600
02400
800
CONTINUE
02500
WRITE (PTR, 200)
02600
C
02700
WRITE (TTY, 9999)
02800
9999
FORMATdH , "END OF PROGRAM")
02900
STOP
03000
END
Figure 4. DECODE Program.
JUNE 1980
INTERFACE AGE 99
I ne last way characters can be stored into a variable is by
using a Hollerith constant as an argument in a subprogram
call. According to subprogram calling conventions, a vari-
able within a subprogram acquires those characters as if they
had been read in or initialized with a DATA statement. The
variable’s content can then be written out, compared, or
manipulated as desired.
The actual contents of any variable containing characters
can be displayed in numeric form as well as character form.
Characters can be read in and written out using the “A” for-
mat, or their numeric equivalent can be stored or retrieved
using any FORTRAN numeric operation. A quick way to
document the numeric equivalent for each character on your
machine is to run the DECODE program (figure 4). This
program reads in characters in “A1 ” format, and prints the
characters and their numeric equivalent on the printer. Once
numeric equivalents are known, character sets (e.g., upper
case, lower case, special) can be defined numerically for an
application (this program was used to specify character sets
for the string package presented further in this article).
MAIN PROGRAM
CALL SETTRC (trace parameters)
CALL A
CALL B
STOP
END
SUBROUTINE A
CALL CALL ('A')
CALL RETR ('A')
RETURN
END
SUBROUTINE B
CALL CALL ('B')
CALL C
CALL RETR ('B')
RETURN
END
SUBROUTINE C
CALL CALL ('C')
CALL RETR ('C')
RETURN
END
Figure 5. Using the trace facility.
TRACE FACILITY
Even with the limited character string capabilities of FOR-
TRAN, we can build one of the four .important tools men-
tioned earlier — the trace facility. This records each sub-
program’s CALL and RETURN. The trace facility built for
this tutorial was designed to be invoked immediately before
and after any subprogram code is executed. Tjius, one part
of the tool must record the fact that a particular subprogram
was called, and another part must signal that the subprogram
is returning to its caller. The subroutines “CALL” and
“RETR” provide these functions respectively.
In order to use the trace facility, a subprogram must invoke
the “CALL” subroutine before it starts to do any work. The
logic of a subprogram should be structured so that there is
always only one entry point and one exit point to the sub-
program. In this way, the subprogram need only call the
“CALL” subroutine at the beginning, and the “RETR” sub-
routine at the end. The argument to both “CALL” and
“RETR” is a single Hollerith constant representing the sub-
program name. The mainline program is required to ini-
tialize the tool by specifying the trace device and a trace
on/off switch (figure 5).
CALL SUBPROGRAM "C" (PUSH) :
RETURN FROM
SUBPROGRAM "C"
NEW TOP AFTER POP
Figure 6. Trace stack data structure and operations.
WO INTERFACE ACE
JUNE 1980
The overall design and implementation of the trace tool
was very dependent upon the nature of the problem. Keep-
ing track of calls and returns requires the saving of the cur-
rent subprogram name when another (child) call is made,
and the restoration of the caller (parent) subprogram name
upon a return. A very common data structure which can handle
this type of problem is called a stack. The term “stack” is
given because the information in the data structure is
manipulated like a stack of coins. Only the top of the stack
can be touched — either to add a new piece of data (push) or
remove the piece of data at the top (pop). Thus a call to a
subprogram would push that subprogram’s name on the top
of the stack, and a return would require the removal of that
name from the stack top (figure 6). Having a data structure
and its operations so closely resembling the problem struc-
ture made the design and coding (figure 7) easy. A simple
one-dimensional array (stack) keeps the subprogram names,
while a single scalar variable (level) keeps track of the top of
the stack (i.e., last assigned element in the array).
00100
SUBROUTINE CALL <' NAME)
00200
DOUBLE PRECISION NAME
00300
LOGICAL TRACE
00400
INTEGER LEVEL, STKSIZ, DEVICE
00500
DOUBLE PRECISION STACK (20)
00600
COMMON /TRCSTK/TRACE, DEVICE, LEVEL, STKSI2, STACK
00700
LEVEL =LEVEL+1
00800
IF ( NOT (LEVEL. LE. STKSIZ)) GOTO 300
00900
STACK ( LEVEL )=NHME
01000
IF ( NOT (TRACE)) GOTO 200
01100
WRITE (DEV ICE, 100) LEVEL, NAME
01200
100
FORMAT (1H , 13, ' CALL: MA8)
01300
200
CONTINUE
01400
300
CONTINUE
01.500
RETURN
01600
END
01700
C
01800
SUBROUTINE RETR(NAME)
01900
DOUBLE PRECISION NAME
82000
LOGICAL TRACE
02100
INTEGER LEVEL, STKSIZ, DEVICE
02200
DOUBLE PRECISION STACK (20)
02300
COMMON /TRCSTK/TRRCE, DEVICE, LEVEL, STKSIZ, STACK
02400
IF (. NOT (LEVEL. GT. 0>> GOTO 700
02500
IF ( NOT. (LEVEL. LE. STKSIZ)) GOTO 500
02600
IF ( NOT (STACK (LEVEL). EQ. NAME)) GOTO 200
02700
IF (. NOT (TRACE)) GOTO 150
02800
WRITE (DEV ICE, 100) LEVEL, NAME
02900
100
FORMAT (1H , 13, ' RETR: ', 1A8)
03000
150
CONTINUE
03100
LEVEL=LEVEL-1
03200
GOTO 400
03300
200
CONTINUE
0340O
WRITE (DEV ICE, 300) NAME, STACK (LEVEL)
03500
300
FORMATdH ,'RETR: MAS,' INSTEAD: ' , 1A8)
03600
LEVEL=LEVEL-1
03700
400
CONTINUE
03800
GOTO 600
03900
500
CONTINUE
04000
LEVEL=LEVEL-1
04100
600
CONTINUE
04200
GOTO 900
04300
700
CONTINUE
04400
WR I TE < DEV I CE, 800 ) NAME
04500
300
FORMATdH , 'NO MATCHING CALL FOR: MAS)
04600
900
CONTINUE
04700
RETURN
04300
END
04900
c
05000
SUBROUTINE SETTRC(TRCON, TRCDEV)
05100
LOGICAL TRCON
05200
INTEGER TRCDEV
05300
LOGICAL TRACE
05400
INTEGER LEVEL, STKSIZ, DEVICE
05500
DOUBLE PRECISION STACK (20)
05600
COMMON /TRCSTK/TRACE, DEVICE, LEVEL, STKSIZ, STACK
05700
TRACE=TRCON
05800
DEVICE=TRCDEV
05900
LEVEL=0
06000
STKSIZ=20
06100
RETURN
06200
END
Figure 7. Trace facility code.
CHARACTER STRING HANDLER
Clearly, FORTRAN is not one of the richest languages
when it comes to character string handling. The current stan-
dard does not even have character data types or operations.
Belter string processing is, however, being considered for
the next version of the industry standard. Even with present
deficiencies, some have proposed techniques for represent-
FUNCTION
CTRAN
BASIC (level II)
Initialize
CALL INISTR
not needed
Declare string
CALL DCLSTR(A,50)
not needed
Read string
CALL GETSTR(TTY,A)
INPUT A$
Write string
CALL PUTSTR (TTY , A)
PRINT A$
Assign constant
no equivalent
A$="LITERAL CONSTANT"
Assign string
CALL MOVSTR(B,A)
B$=A$
Concatenate
CALL MOVSTR(B / CATSTR(A / C) )
B$=A $+C$
Repeat
CALL MOVSTR(B,REPSTR(A,5))
partial functionality with STRING$
Take a Piece
CALL MOVSTR(B,SUBSTR(A,3,7))
B$=MID$(A$,3,7)
Change a Piece
CALL MOVSTR(SUBSTR(A, 2, 5) ,B)
no equivalent
Length of String
S=LENSTR(A)
S=LEN ( A$)
Find start of a pattern
P=FNDSTR(A, B)
no equivalent
Null string
CALL NULSTR(A)
A$=""
Blank string
CALL BLKSTR(A)
no equivalent
Get special character set
CALL GETSPL(A)
A$="! @#$%A &*()+__: . , ; \ , <>"
C equality
Compare for / less than
| greater than
IF(EQSTR(A, B) ) . . .
IF(LTSTR(A,B))...
IF(GTSTR(A, B) ) . . .
IF A$=B $. . .
IF A$<B$...
IF A $ >B $ . . .
( HIGH VALUES
bet to V. |_ow VALUES
CALL GETHGH (A)
CALL GETLOW(A)
no equivalent
Figure 8. CTRAN interfaces compared with BASIC.
JUNE 1980
INTERFACE AGE 101
ing variable length character strings. Others have expanded
upon these earlier concepts and developed a good set of
character handling subroutines.
There are many good reasons for developing this type of
software tool, especially in the micro-environment. A string
package generalizes the local environment around an appli-
cation program, providing a simple and consistent level of
interface. In this way, the application logic is only concerned
with the manipulation of character strings as it relates to the
problem solution. Details about the form of storage and I/O
are hidden from the application level. Certainly these quali-
ties enhance the ability to move programs from one system
or compiler to another with little or no change — a distinct
advantage of FORTRAN.
A good character string package for FORTRAN must pro-
vide several functions:
• declare a string variable
• read in/write out a string from/to a device
• build a string from other strings
• break a string apart
• scan a string for a pattern
• determine a string’s length
• compare strings to each other
The character string package developed for this tutorial
provides all the above functions, plus some important utili-
ties. Interfaces shown in figure 8 were forced to be imple-
mented by subroutines, however, due to compiler limita-
tions. This package will be called CTRAN in this series.
A simple test showing how an application program actu-
ally uses the CTRAN package is in figure 9. Ffere, simple
read-first logic is used to read in a string and then echo what
was entered. The program stops when no characters are
entered. Tracing is initialized since all tools in this tutorial use
that facility to help the programmer test an application.
00100
INTEGER TTV,KEV
00200
INTEGER STRING
00300
LOGICAL TRACE
00400
DATA TTY/1/, KEY/1/
00500
C
00600
WR I TEC TTY, 100)
00700
100
FORMAT C1H , 'START OF PROGRAM')
00800
TRACE*. TRUE.
00900
CALL SETTRCC TRACE, TTY)
01000
CALL INISTR
01100
CALL DCLSTRC STRING, 30)
01200
C
01300
NR I TEC TTY, 200)
01400
200
FORMAT C1H , 'STRING?')
01500
CALL GETSTRCKEY, STRING )
01600
C
01700
300
IF C0 . EQ. LENSTRC STRING)) GOTO 500
01800
NR I TEC TTY, 400)
01900
400
FORMAT C1H , 'STRING ENTERED. ')
02000
CALL PUTSTRC TTY, STRING)
02100
NR I TEC KEY, 200)
02200
CALL GETSTRCKEY, STRING)
02300
GOTO 300
02400
500
CONTINUE
02500
C
02600
NR I TEC TTY, 9999)
02700
9999 FORMAT C1H , 'END OF PROGRAM' >
02800
STOP
02900
END
Figure 9. Echo Program.
Experience with building and using a character handling
package of this type has identified three important optimiza-
tions for micros. First, any portion dealing with input/output
can be recoded to take advantage of a particular machine,
compiler and storage size. This will increase the speed of the
software if I/O routines have very general algorithms. Sec-
ond, CTRAN uses “A1 ” format with an INTEGER array for
its central string space. Recoding to use the most storage effi-
cient data type for a particular machine could certainly
reduce wasted storage. Lastly, all internal operations should
be done with the fastest INTEGER arithmetic possible. This
may be in conflict with the previous recommendation, and
usually space is more of a problem than small inefficiencies
in speed.
WORD ISOLATOR
Now we have enough tools to make our first set of real
filters. The string handling package divorces us from the
details of variable length character strings, and allows us to
concentrate on application details. The trace facility will be
employed to help test the software we build. Keeping in
mind those four major programming aids mentioned in the
introduction, we can build a level of filters which provide a
common level of support — a word isolator.
We can define a “word” as being a collection of alpha-
numeric characters surrounded by special characters. Special
characters are symbols not commonly found in a word (e.g.,
comma, period, colon, question mark, blank, etc.). The ac-
tual text containing those words should be considered as a
single stream of characters to the word isolator. This allows
the details of how the text is actually stored to be hidden from
the real problem of forming a word. We therefore have two
major parts to the problem. The first is forming words from a
stream of characters. The second involves creating a stream
of characters from some sort of physical storing of text.
Having stated our two major requirements, we can design
these two important parts (figures 10 and 1 1). The design
representation used is the Nassi-Schneiderman Structured
Flowchart forms. For this exercise, we are not taking into
account the problem of detecting when the entire input is ex-
hausted. We are also limiting our input device to the key-
board, both for simplicity and to allow you to easily imple-
ment these programs.
GET THE FIRST CHARACTER
OF THE WORD
GET THE NEXT CHARACTER
FROM THE STREAM
2
UNTIL THIS CHARACTER IS A
SPECIAL CHARACTER:
APPEND THIS CHARACTER
TO THE WORD WE ARE
CURRENTLY BUILDING
3
GET THE NEXT CHARACTER
FROM THE STREAM ^
[H
Figure 10. Design of Get Word filter.
102 INTERFACE AGE
JUNE 1980
Figure 11. Design of Get Next Character filter.
Figure 12. Word isolator general design.
Using these two filters, a general design was established
(figure 12). This design representation uses Hierarchical In-
put Process Output diagrams, including all the major func-
tions required to perform word isolation. During implemen-
tation, this design was used to develop the major sub-
programs. Other subprograms were built to provide a clean
way of remembering and retrieving important information
shared among many subprograms (figure 13). Additional
design was needed to define these, but discussion of this is
beyond the scope of this tutorial. A simple test of the word
isolator shows how easy it is to get a word from text with this
filtering mechanism (figure 14).
00100
c
—GET CHRR STRING VRRIRBLE
08200
C
003:00
SUBROUTINE GETCS<CHRR)
00400
INTEGER CHRR
00500
INTEGER CHRSTR
00600
COMMON /COMCS/CHRSTR
00700
CRLL CRLLC'GETCS ')
00800
CHRR=CHRSTR
00900
CRLL RETRC 'GETCS ')
01000
RETURN
01100
END
01200
C
01200
C
—GET END OF LINE POINTER
01400
C
01500
SUBROUTINE GETEL.PCENDLIN)
01600
INTEGER ENDLIN
01700
INTEGER ENDPTR
01800
COMMON /COMELP/ENDPTR
01900
CRLL CRLLC'GETELP '>
02000
ENDLIN=ENDPTR
02100
CRLL RETRC 'GETELP ')
02200
RETURN
021500
END
02400
c
02500
c
—GET FIRST CHRR IN WORD
02600
c
02700
SUBROUTINE GETFCRC DEV ICE, CHRR)
02800
INTEGER DEVICE, CHRR
02802
LOGICRL SPLCHR
02900
CRLL CALL< 'GETFCR ')
03000
CRLL GETNCRCDEVICE, CHRR)
03002
CRLL SPECRLC SPLCHR, CHRR)
03100
100
IF C. NOT. SPLCHR) GOTO 200
03200
CRLL GETNCRCDEVICE, CHRR)
03202
CRLL SPECRLC SPLCHR, CHRR)
03300
GOTO 100
03400
200
CONTINUE
03500
CRLL RETRC X GETFC:R O
03600
RETURN
03 700
END
83300
C
03900
C
—GET LINE STRING
04000
C
04100
SUBROUTINE GETLSCLINE)
04200
INTEGER LINE
04300
INTEGER LINSTR
04400
COMMON /COMLIN/LINSTR
04500
CRLL CRLLC'GETLS O
04600
LINE=LINSTR
04700
CRLL RETRC 'GETLS ')
04800
RETURN
04900
END
05000
C
05100
c
-GET NEXT CHRR POINTER
05200
C
05300
SUBROUTINE GETNCPCCHRPTR)
05400
INTEGER CHRPTR
JUNE 1980
INTERFACE ACE 103
05500 INTEGER NXTPTR
05600 COMMON /COMNCP/NXTPTR
05700 CALL CALL("GETNCP ")
05800 CHRPTR=NXTPTR
05900 CALL RETR("GETNCP ')
06080 RETURN
06100 END
06200 C
06300 C GET NEXT CHAR
06400 C
06500 SUBROUTINE GETNCR( DEV ICE, CHAR)
06600 INTEGER DEVICE, CHAR
06700 INTEGER LINE, PIECE
06800 INTEGER CURCHR, ENDLIN
06900 CALL CALL("GETNCR ")
07000 CALL GETLSCLINE)
07100 CALL GETNCP( CURCHR)
07200 CALL GETELP( ENDLIN)
07300 IF (.NOT. (CURCHR GE. ENDLIN)) GOTO 100
07400 CALL GETSTR( DEV ICE, LINE)
07500 CURCHR-0
07600 100 CONTINUE
07700 CURCHR=CURCHR+1
07702 CALL SETNCP( CURCHR)
07800 CALL SUBSTR(PIECE, LINE, CURCHR, 1)
07806 CALL MOVSTR( CHAR, PIECE)
07900 CALL RETR( "GETNCR ">
08000 RETURN
08100 END
08200 C
08300 C GET WORD
08400 C
08500 SUBROUT I NE GETWRD ( DEV I CE, WORD )
08600 INTEGER DEVICE, WORD
08700 INTEGER CHAR, MORE
08702 LOGICAL SPLCHR
08800 CALL CALL(" GETWRD '>
08900 CALL GETCS(CHAR)
09000 CALL GETFCR( DEV ICE, CHAR)
09100 CALL MOVSTR( WORD, CHAR)
09200
09202
09300
09302
09400
09500
09502
09600
09700
09800
09900
10000
10100
10200
10300
10400
10500
10600
10700
10800
10900
11000
11100
11200
11300
11400
11500
11600
11700
11800
11900
12000
12100
12200
12300
12400
12500
12600
CALL GETNCR( DEV ICE, CHAR)
CALL SPECAL( SPLCHR, CHAR)
100 IF (SPLCHR) GOTO 200
CALL CONCAT(MORE, WORD, CHAR)
CALL MQVSTRcWGRD, MORE)
CALL GETNCR( DEV ICE, CHAR)
CALL SPECAL( SPLCHR, CHAR)
GOTO 100
200 CONTINUE
CALL RETRC GETWRD ')
RETURN
END
C
C 1 NIT GET WORD PACKAGE
C
SUBROUTINE INIWRD
INTEGER CHAR, LINE
INTEGER LINSIZ
CALL CALL ("INIWRD ')
CALL DCLSTR(CHAR, 1)
CALL SETCS(CHAR)
LI NS I 2=80
CALL DCLSTR(LINE, LINSIZ)
CALL SETLS(LINE)
CALL SETELP(LINSIZ)
CALL SETNCP(LINSIZ+1)
CALL RETR(" INIWRD ')
RETURN
END
C
C SET CHAR STRING VARIABLE
C
SUBROUTINE SETCS(CHAR)
INTEGER CHAR
INTEGER CHRSTR
COMMON /COMCS/CHRSTR
CALL CALL("SETCS ">
CHRSTR=CHAR
12700
12800
12900
13000
13100
13200
13300
13400
13500
13600
13700
13800
13900
14000
14100
14200
14300
14400
14500
14600
14700
14800
14900
15000
15100
15200
15300
15400
15500
15600
15700
15800
15900
16000
16100
16200
16300
16400
16500
16600
16700
16800
16900
17000
17002
17100
17200
17300
17306
17400
17500
18000
18100
18200
18300
CALL RETR("SETCS ')
RETURN
END
C
C SET END OF LINE POINTER
C
SUBROUTINE SETELPC ENDLIN)
INTEGER ENDLIN
INTEGER ENDPTR
COMMON /COMELP/ENDPTR
CALL CALLC'SETELP ")
ENDPTR=ENDLIN
CALL RETR("SETELP ')
RETURN
END
C
C SET LINE STRING
C
SUBROUTINE SETLS(LINE)
INTEGER LINE
INTEGER LINSTR
COMMON /COMLIN/LINSTR
CALL CALL('SETLS ')
LINSTR=LINE
CALL RETR("SETLS • ">
RETURN
END
C
C SET NEXT CHAR POINTER
C
SUBROUTINE SETNCP ( CHRPTR )
INTEGER CHRPTR
INTEGER NXTPTR
COMMON /COMNCP/NXTPTR
CALL CALL ("SETNCP ")
NXTPTR=CHRPTR
CALL RETR( "SETNCP ')
RETURN
END
C
C TEST FOR SPECIAL CHAR
C
SUBROUTINE SF‘ECAL( BOOL, CHAR)
INTEGER CHAR
LOGICAL BOOL
INTEGER SPLCHR, POS
CALL CALL("SPECAL ")
CALL GETSPLC SPLCHR)
CALL FNDSTR(POS, CHAR, SPLCHR)
IF (0 . EQ. POS) BGOL=. FALSE.
IF (0 . NE. POS) BOOL= TRUE.
CALL RETR("SPECAL ")
RETURN
END
C
Figure 13. Code for word isolator.
00100
INTEGER TTY, KEY, PTR
00200
INTEGER WORD, ENDWRD
00300
LOGICAL TRACE, DONE
00400
DATA TTY/1/, KEY/1/, PTR/2/, TRACE/. TRUE. /
00500
c
00600
WRITE (TTY, 100)
00700
100
FORMAT (1H , "START OF PROGRAM")
00800
CALL SETTRC( TRACE, PTR)
00900
CALL INISTR
01000
CALL INIWRD
01100
CALL DCLSTRCWORD, 30)
01200
CALL DCLSTR( ENDWRD, 30)
01300
C
01400
WRITE (TTY, 200)
01500
200
FORMAT (1H .."TERMINATING WORD?")
01600
CALL GETWRD (KEY, ENDWRD)
104 INTERFACE ACE
JUNE 1980
01700
c
01800
WRITE(TTY, 250)
01900
250
FORMAT (1H , 'WORD?')
02000
CALL GETWRD(KEY, WORD)
02002
CALL EQSTR(DONE, WORD, ENDWRD)
02100
300
IF (DONE) GOTO 400
02200
WRITE (TTY, 350)
02300
350
FORMAT (1H , 'WORD ENTERED. . . ')
02400
CALL PUTSTR(TTY, WORD)
02500
WRITE (TTY, 250)
02600
CALL GETWRD( KEY, WORD)
02602
CALL EQSTRCDONE, WORD, ENDWRD )
02700
GOTO 300
02800
400
CONTINUE
02900
C
03000
WRITE (TTY, 9999)
03100
9999
FORMAT (1H , 'END OF PROGRAM')
03200
STOP
03300
END
Figure 14. Using the word isolator.
SORTING APPLICATION
Now we can build an application to see not only how to ef-
fectively use these tools, but how new tools can be made to
solve immediate and future problems. The application
chosen is one which prints a sorted list of words with their
frequencies of occurrence (a good use of this application is
to check all words with a frequency of one for spelling errors).
One function we will need is extracting the next word from
the text. Obviously, the word isolator can handle that job.
Since the words are originally in unsorted order, another
function must put each word in sorted sequence. Duplicate
words imply incrementing a frequency counter for the
duplicate word. The last required function is the printing of
each sorted word with its associated frequency.
Sorting is merely the reorganization of data into some
ordered form. An organization of data implies that the data
has structure. This structure must, therefore, provide a way
of keeping the data in sorted order. The previous chapter of
this tutorial dealt with a method of sorting called the straight
insertion sort. This method involved finding the correct place
in a linear structure to insert the newest element so that the
structure would always remain in sorted order. Recall also
the Alibi concept was used in the algorithm, whereby all
elements of the linear structure beyond the insertion point
were physically moved to make room for the new element.
We will use this same basic algorithm and linear structure
for our sort. However, instead of using an array to implement
the linear structure, we will use what is called a linked list. In
general, a linked list is a logical organization of individual
items of data composed of numerous items called nodes,
each node having several fields. The organization is called
logical because, instead of each node being physically next
to each other (like an array), it is referenced and organized by
pointers (sometimes called links). Nodes need not be in
physical order to be in sorted order.
For our application, each node will contain a word field
and a frequency count field. While there are more complex
data structures, we have chosen a simple one to introduce
linked concepts: line them up in a single list or queue. In
fact, the linear linked list is a pretty efficient structure when
used in conjunction with the sort by insertion algorithm. For
our application, each node will be connected to other nodes
via a forward pointer and a backward pointer. Thus, each
node can immediately reference (point to) the previous or
next nodes in the list. This is done to completely separate the
logic of scanning from the logic of inserting. When doing
any work with linked lists, it is always advisable to draw a pic-
ture to help better understand what the structure looks like
(figure 1 5).
GIVEN A NODE HAVING
THE FOLLOWING GRAPHICAL
REPRESENTATION :
WORD
FORWARD
POINTER
BACKWARD
POINTER
A SAMPLE LINEAR LIST
CAN BE DRAWN AS:
NOTE: The symbol denotes a null pointer specifying the end of the list.
Figure 15. Sample linear list of sorted words.
After seeing the form of the data structure, three conclu-
sions regarding the straight line insertion sort algorithm can
be reached. First, in order to find the insertion point, the
algorithm can scan through the list by following either the
forward or backward pointers. Second, nodes in the list need
not be physically copied to make room for a new insertion.
Only pointers need changing to keep nodes in sorted order
— hence an Alias (name change) operation is all that is re-
quired (figure 16).
BEFORE INSERTION :
CONNECT NEW NODE FIRST:
CORRECT POINTERS IN
ORIGINAL NODES:
Figure 16. Inserting into list by Alias operations.
JUNE 1980
INTERFACE AGE 105
Lastly, proper initialization of the data structure can reduce
the logic needed to insert a new node during special situa-
tions (e.g., when list is empty or at either end). In our case,
building a list containing two nodes, one with low values and
one with high values, will guarantee that all additions use the
same insertion logic (figure 17). This concept prompted the
implementation of the GETLOW and GETHIGH functions
in the CTRAN package (figure 8). These functions are also
in other languages such as COBOL and PL/I.
The implementation of “nodes” in the FORTRAN lan-
guage is done using the RECORD data primitive. Each field
in a node is represented by an array. In our case, the arrays:
WRDLST, WRDFRQ, WRDFL, WRDBL hold values for
word, frequency, forward pointer, and backward pointer
respectively. A single INTEGER variable is used to index into
the same position of each array to get field values for a node.
Knowing about all these concepts led to a general design
where words were first inserted into a list, and then the com-
plete list of words and frequencies were printed (figure 18).
Separate subroutines were designed to hide the details of
sorting into the list and getting sorted words from the list.
This technique allows the sorting logic to change while the
application program remains unaltered. These subroutines
(SRTWRD - sort word, and GETSWF - get sorted word and
frequency) become the two other filters used by the applica-
tion along with the Get Word filter (figure 1 9 — a different
way of using COMMON is given so that you can compare it
to the previous style of usage in the Word Isolator). With
such a clean design, writing an actual application using the
DADT word facility is easy (figure 20).
00100
C
00200
C
—ADD WORD INTO SORTED WORD LIST
00300
C
00400
SUBROUT I NE flDDWRD ( WORD, NODE >
00500
INTEGER WORD, NODE
00600
INTEGER NEWWRD, NEWNOD, NODBL
00700
LOGICAL SAME
00800
INTEGER WRDLST (100), WRDFL (100), WRDBL <100), WRDFRQ (100)
00900
COMMON /COMLST /WRDLST
01000
COMMON /COMFL/WRDFL
01100
COMMON /COMBL/WRDBL
01200
COMMON /COMFQ/ WRDFRQ
01300
COMMON /COMNEW/NEWNOD
01400
CALL CALL < ' ADDWRD ')
01402
CALL DMPNOD(NODE)
01500
CALL EQSTRCSAME, WORD, WRDLST ( NODE > )
01600
IF < NOT SAME) GOTO 100
01700
WRDFRQ ( NODE ) = WRDFRQ ( NODE > +1
01702
CALL DMPNOD(NODE)
01800
GOTO 280
01900
100
CONTINUE
02000
CALL DCLSTR( NEWWRD, 30)
02100
CALL M0VSTR( NEWWRD, WORD)
02200
NEWN0D=NEWN0D+1
02300
WRDLST < NEWNOD ) =NEWWRD
02400
WRDBL < NEWNOD ) =WRDBL < NODE )
02500
WRDFL ( NEWNOD )=N0DE
02600
NODBL=WRDBL < NODE )
02700
WRDFL ( NODBL ) =NEWN0D
02800
WRDBL < NODE ) =NEWN0D
02900
WRDFRQ C NEWNOD >=1
02902
CALL DMPNODC NEWNOD)
03000
200
CONTINUE
03100
CALL RETR(' ADDWRD ')
03200
RETURN
03300
END
03400
C
03500
C
—BUILD SORTED WORD LIST
03600
C
03700
SUBROUTINE BLDLST (DEVICE)
03800
INTEGER DEVICE
03900
INTEGER WORD, ENDWRD
04000
LOGICAL DONE
04100
CALL CALL ( 'BLDLST ')
04200
CALL DCLSTR(WORD, 30)
04300
CALL DCLSTR( ENDWRD, 30)
04400
WRITE (DEV ICE, 100)
04500
100
FORMAT (1H , 'TERMINATING WORD?')
04600
CALL GETWRD( DEV ICE, ENDWRD)
04700
WRITE (DEV ICE, 150)
04800
150
FORMAT (1H , 'WORD 7 ')
04900
CALL GETWRD( DEV ICE, WORD)
05000
CALL EQSTR(DONE, WORD. ENDWRD)
05100
200
IF (DONE) GOTO 300
05200
CALL SRTWRD (WORD)
05300
WRITE (DEV ICE, 150)
05400
CALL GETWRD( DEV ICE, WORD)
05500
CALL EQSTR(D0NE, WORD, ENDWRD)
05600
GOTO 200
05700
300
CONTINUE
05800
CALL RETR( 'BLDLST ')
05900
RETURN
06.000
END
06:100
c
06200
c
—GET SORTED WORD AND FREQ
06300
C
06400
SUBROUTINE GETSWF (WORD. FREQ, DONE)
06500
INTEGER WORD, FREQ
06600
LOGICAL DONE
06700
INTEGER L0WN0D, HGHNOD, SRTNOD
06800
INTEGER WRDLST (100), WRDFRQ(100), WRDFL(100)
06900
COMMON /COMLST /WRDLST
07000
COMMON /COMFRQ/WRDFRQ
07100
COMMON /COMFL/WRDFL
07200
COMMON /COMLHN/LOWNOD, HGHNOD
07300
COMMON /COMSN/SRTNOD
07400
CALL CALL ('GETSWF ')
07500
IF (SRTNOD . EQ. LOWNOD) SRTN0D=WRDFL( SRTNOD)
07600
IF (.NOT (SRTNOD EQ. HGHNOD)) GOTO 100
07700
D0NE=. TRUE
07800
GOTO 200
07900
100
CONTINUE
07902
CALL DMPN0D( SRTNOD)
08000
WORD=WRDLST( SRTNOD)
08100
FREQ= WRDFRQ ( SRTNOD)
08200
D0NE=. FALSE
08300
SRTNOD*=WRDFL( SRTNOD)
08409
200
CONTINUE
08500
CALL RETR( 'GETSWF ')
06:600
RETURN
00700
END
106 INTERFACE AGE
JUNE 1980
00800
C
08900
C
— INIT SORT WORD PACKAGE
09000
C
09100
SUBROUTINE INISRT
09102
INTEGER LOWWRD, HGHWRD
89200
INTEGER LOWNOD, HGHNOD, NEWNOD, SRTNOD
09300
I NTEGER WRDLST C 100 ) , WRDFRQ < 100 ) , WRDBL (100 ) , WRDFL C 100 )
09400
COMMON /COMLST /WRDLST
09500
COMMON /COMFRQ/WRDFRQ
09600
COMMON /COMBL/WRDBL
09700
COMMON /COMFL/WRDFL
09800
COMMON /COMLHN/LOWNOD, HGHNOD
09900
COMMON /COMNEW/NEWNOD
10000
COMMON /COMSN/SRTNOD
10100
CALL CALLC'INISRT ')
10200
L0WN0D=1
103-00
HGHN0D=2
10400
NEWNOD=HGHNOD
10500
SRTNOD=LOWNOD
10600
CALL DCLSTR < LOWWRD 30 )
10700
CALL GETL0I4C LOWWRD)
10800
WRDLST (LOWNOD ) =LOWWRD
10900
WRDFRQ ( L 0 WNOD ) =0
11000
WRDFL ( LOWNOD ) =HGHNOD
11100
WRDBL ( LOWNOD ) =0
11200
CALL DCLSTR (HGHWRD. 30)
11300
CALL GETHGH< HGHWRD)
11400
WRDLST ( HGHNOD ) =HGHWRD
11500
WRDFRQ ( HGHNOD )=0
11600
WRDFL ( HGHNOD )=0
11700
WRDBL ( HGHNOD ) =LOWNOD
11800
CALL RETRC ' INISRT '>
11.900
RETURN
12000
END
12100
C
12200
C
—PRINT SORTED WORD LIST
12300
C
1^400
SUBROUTINE PRTLSTCDEVICET
12508
INTEGER DEVICE
12600
INTEGER WORD. FREQ
12700
LOGICAL DONE
12800
CALL CALLC'PRTLST ')
12900
CALL GETSWF(WORD. FREQ. DONE)
13000
100
IF
(DONE) GOTO 300
13100
CALL PUTSTRC DEV ICE. WORD)
13200
WRITE (DEV ICE. 200) FREQ
13300
200
FORMAT C1H .15)
13400
CALL GETSWFC WORD. FREQ, DONE)
13500
GOTO 100
13600
300
CONTINUE
13700
CALI. RETRC 'PRTLST ')
13800
RETURN
13900
END
14000
C
14100
c
—SEARCH SORTED WORD LIST
14200
c
14300
SUBROUTINE SCHLSTCWORD. NODE)
14400
INTEGER WORD. NODE
14500
INTEGER LSTWRD
14600
LOGICAL EQUAL. GREATR
14602
INTEGER LOWNOD. HGHNOD
14700
I NTEGER WRDLST < 100 ) . WRDFL ( 100 )
14800
COMMON /COMLST /WRDLST
14802
COMMON /COMLHN/LOWNOD. HGHNOD
14900
COMMON /COMFL/WRDFL
15000
CALL CALLC 'SCHLST ')
15100
N0DE=L0WN0D
15102
CALL DMPNOD(NODE)
15200
LSTWRD=WRDLST (NODE )
15300
CALL EQSTRC EQUAL. WORD. LSTWRD)
15400
CALL GTSTRCGREATR, LSTWRD. WORD)
15500
100
IF
(EQUAL OR GREATR) GOTO 200
15600
NODE=WRDFL C NODE )
15602
CALL DMPNOD C NODE )
15700
LSTWRD=WRDLST ( NODE )
15800
CALL EQSTRCEQUAL, WORD, LSTWRD)
15900
CALL GTSTRCGREATR, LSTWRD, WORD)
16000
GOTO 100
16100
200
CONTINUE
16200
CALL RETRC 'SCHLST ')
16300
RETURN
16400
END
16500
c
16600
c
-SOR
T WORD
16700
C
16800
SUBROUTINE SRTWRD(WORD)
16900
INTEGER WORD
17000
INTEGER INSNOD
17100
CAL
JL CALLC 'SRTWRD ')
17200
CALL SCHLSTCWORD. INSNOD)
17300
CAL
L ADDWRDCWORD, INSNOD)
17400
CAL
1 RETRC 'SRTWRD ')
17500
RET
URN
17600
END
T
17602 C
17604 SUBROUTINE DMPNODCNODE)
17606 INTEGER NODE
17608 INTEGER WRDLSTC100), WRDFRQC100), WRDBLC100), WRDFLC100)
17610 COMMON /COMLST /WRDLST
17612 COMMON /COMFRQ/WRDFRQ
17614 COMMON /COMBL/WRDBL
17616 COMMON /COMFL/WRDFL
17618 CALL CflLL<"DMPNOD ')
17620 WRITEC2, 1)N0DE
17622 1 FORMAT (1H , 'NODE 2 ', 18)
17624 WRITE C2, 2) WRDLST (NODE)
17626 2 FORMAT < 1H , 'WORD=',I 8)
17628 WR I TE C 2, 3 ) WRDFRQ ( NODE )
17630 3 FORMAT (1H , 'FREQ=', 18)
17632 WR I TE ( 2, 4 ) WRDFL ( NODE )
17634 4 FORMAT (1H , 'FL=', 18)
17636 WR I TE ( 2, 5 ) WRDBL ( NODE )
17638 5 FORMATC1H , 'BL=', 18)
17640 CALL RETRC 'DMPNOD ')
17642 RETURN
17644 END
Figure 19. Word sorter and frequency count code.
80100
INTEGER TTY, KEV, PTR
00200
LOGICAL TRACE
00300
DATA TTV/1A KEY/1A TRACE/. TRUE. A PTR/2/
00400
WRITE (TTY, 100)
00500
100
FORMAT (1H , 'START OF PROGRAM')
00600
CALL SETTRCC TRACE, PTR)
00700
CALL INISTR
00800
CALL INIWRO
00900
CALL INISRT
01000
CALL BLDLST (KEY)
01100
CALL PRTLST(TTY)
01200
WRITE (TTY, 9999)
01300
9999
FORMAT (1H , 'END OF PROGRAM')
01400
STOP
01500
END
Figure 20. Using the word sorter.
CONCLUSION
With all this talk of building tools upon tools, a word or two
of caution is in order. One can spend all one’s time building
tools, and not solving problems. The microcomputer should
be a help to the small business, but it cannot if only tools are
built and not applications. Thus careful assessment must be
made before plunging into the construction of a new soft-
ware tool.
Another common area of trouble is the proper selection
and use of software utilities when your toolbox is large. Hav-
ing a large set of software capabilities can often lead one into
choosing a bad approach to implementing a problem solu-
tion. A well-documented and complete understanding of
what is available will help you choose the right tool for the
right job.
Experience in constructing these tools has pointed out that
the microcomputer environment is still somewhat unpredict-
able. Several compiler or run-time limitations caused long
delays in testing by having to track down difficult bugs. The
trace facility made the identification of those problem areas
much easier, however. It is recommended that the trace tool
be given the power to display input and output parameters of
the called subprograms. This additional feature was the big-
gest help during testing.
Probably the major advantage in understanding the soft-
ware tool concept is that one can stop getting caught up in
the “invented here syndrome.” Most of the software appli-
cation shops today do not really build upon the work of
others. In fact, most applications are still built over and over
again from scratch because past work is not in a reusable
form. Hopefully, this article will be a start towards the build-
ing of better engineered application software in the micro-
environment. □
JUNE 1980
INTERFACE AGE 107
Interfaces
I ■ .By Richard A. Leary l
While each major microprocessor has one or more LSI
peripheral interface devices specifically designed for that pro-
cessor, occasions may arise when those “matched” hard-
ware blocks do not satisfy the user’s needs. It is also possible
that changes to existing equipment may force one into mix-
ing devices of one family with those of another. As a result of
the latter kinds of pressure, I found myself in a position
where I had to interface I/O devices of the 6800/6502
family to a Z-80. What follows is both a synopsis of my prob-
lems and a description of what I did to solve those problems.
The 6800/6502 devices I used were part of wire-wrapped
I/O board I had built over a year earlier to use with a wire-
wrapped 6502 CPU board. In switching to a Z-80 CPU
(primarily due to the birth of 6502 software) the problem was
how to make the transition with minimum trouble and ex-
pense. While both the CPU and the I/O board used S-100
prototype boards and the rest of my system used the S-100
bus, that fact alone does not guarantee compatibility.
Although I thought I had carefully checked the I/O board
and the rest of the system for compatibility with the Z-80
CPU board, the problems started building up early. When I
first attempted to run my system with the Z-80 CPU in place,
nothing seemed to happen. My initial reaction, since I do not
have a front panel and thus rely upon a monitor in ROM to
bring the system up, was that somehow my 1 K hand
assembled monitor, hand burned into a 2708, was in error.
While there was certainly ample opportunity for that process
to have gone astray, that proved not to be the case. Although
I suspected the CPU-I/O interface from the start, I spent
many hours investigating the possibility of a ROM error.
At this point, it is well to back up a minute and look at how
the 6502 was originally interfaced to the I/O devices. Figure
1 shows an example of the interface in semi-block diagram
form. Note that while the key interface signals are shown, I
have not shown all the on-board decoding and buffer enabl-
ing logic nor have I shown other signals which are not ger-
maine to this discussion.
As can be seen, I had defined a new bus line (66) as “I/O.”
This line was simply the output of a comparator on the CPU
board which was true whenever a preselected page in memory
was addressed. As the 6502 and 6800 have no I/O instruc-
tions like the 8080 or Z-80, this preselected page defined
the range of I/O addresses to be used in my system. The
“I/O” signal fed all I/O devices attached to the bus. What
that meant was that any I/O device need only look for the
“I/O” signal and then decode the 8-bit port number much
as is done for the 8080 or Z-80. This demonstrated some
measure of S-100 compatibility for I/O instructions.
To switch to the CPU I changed the 6502 interface to
what is shown in Figure 2. Since I wanted to retain the ability
to interface both CPUs with my system merely by switching
CPU boards, this dual interface was implemented with some
logic on the I/O board which sensed which CPU board was
being used and set a switch accordingly. The insides of that
switch will not be discussed in detail since it was a simple
piece of selection logic. Its sole purpose was to determine
what signal would be used for the ENABLE signal going to
the 6820. As before, for the 6502, that signal was 02. In
Figure 2 it is clear that the only real change, other than the
introduction of the switch discussed above, is in how the CS
(chip select) signal for the I/O device is generated.
108 INTERFACE ACE
JUNE 1980
CPU 1/ o
Figure 2 . Modified 6502-6820 interface.
While in Figure 1
CS = PORTSELECTH/O (1)
in Figure 2
CS = PORTSELECT*(SINP + SOUT) (2)
However, if the terms SINP and SOUT in equation (2) are
decomposed, equation (2) really says
CS = PORTSELECT*([l/O*R/W] + [l/O*R7W*02]) (3)
Ignoring that extra 02 term in this last equation (3), it is
clear that equation (1) and equation (2) are equivalent. Why
the 02 term can be ignored is not immediately obvious but is
the result of the 6800/6502 I/O device family character-
istics. While the CS inputs must be stable during the EN-
ABLE period, they do not have to be stable prior to that time.
As ENABLE in this case is 02, the fact that one of the factors
in determining CS involves an AND with 02 means that the
I/O device in Figure 2 should work just as it did in Figure 1 .
In actual fact that is what happens.
Then why change? The answer is simple; an S-1 00 Z-80
CPU generates SINP and SOUT, not I/O. So this change
was one that I thought prudent in order to make the system
“S-1 00 compatible. ”
The next question was what should be used for the EN-
ABLE signal when operating with the Z-80 CPU. My initial
hope that I could continue to use 02, now the Z-80 0 clock,
was quickly put to rest without having to reach the bread
board stage. The 0 signal (shown on Figure 3 which was ex-
tracted from Zilog Z-80 CPU Technical Manual) which for
my CPU, an Ithaca Audio board, becomes the S-1 00 02
(24) obviously does not satisfy the ENABLE timing re-
quirements shown in Figures 4a and 4b. The later two
figures were extracted from the Motorola M6820 data sheet
and are typical of all 6800 family devices. What was needed
was a signal that matched the Z-80 CPU’s actual read and
write timing. Since SINP and SOUT are derived in the Z-80
CPU board as
SOUT = IORQ # WR (4)
and
SINP = IORQ*RD (5)
However, one other requirement of the I/O devices had to
be satisfied. The ENABLE signal, as shown in Figure 4, had
to continue to clock-like fashion even after the device was ad-
dressed in order for the peripheral handshaking and interrupt
response functions to work correctly. If enable only consisted
of the following:
ENABLE = SINP + SOUT (6)
it is clear that this last requirement would not be met.
One feature of the Z-80 offered some promise. Unlike
either the 80 80, 6 800, or 6502, the Z-80 generates a
special signal, RFSH, designed to be used to refresh dynamic
memories. As Figure 5 indicates, this signal has some inter-
esting characteristics which meant it might satisfy the require-
ments discussed previously. First, it occurs during every Ml ,
i.e. OP-Code fetch, cycle. That means that while not occurring
JUNE 1980
INTERFACE AGE 109
Tl
T 2
t 3
T 4
Tl
-J
A0-A15
T po
1 REFRE
SH ADDR.
I
J — \
MREQ
l
r
RD
r
WAIT
Mi “
--
—
—
i
\
—
\
DB0-DB7
LIU
/
RFSH
\
1
Figure 5. Z-80 Op Code Fetch Cycle.
nearly as often as a 6800/6502 02 clock, it still occurs
often enough to have negligible effect on most low speed
I/O operations. Second, it occurs during a time when no
I/O devices can possibly be addressed, i.e. IORQ and hence
SINP and SOUT cannot be true. That means t hat false I/O
reads or writes cannot happen. Finally, RFSH duration ex-
ceeds the ENABLE minimum width requirements of 470 jusec
even for a 4 MHz system.
The next effect was that my initial try at interfacing the I/O
board to the Z-80 CPU defined ENABLE as
ENABLE = RFSH +SINP + SOUT (7)
This equation would change the switch selected ENABLE
signal for the Z-80 to what is shown in Figure 6. (As an aside,
note that I moved RFSH to pin 66 instead of pin 67 as it
originally existed on the CPU board. This change was made
since my three Vector Graphic 8K RAM boards all used pin
67 as PHANTOM.)
As already revealed, this approach did not work. Without a
logic analyzer or a good oscilloscope, the trouble shooting
was not easy. Use of a logic probe revealed that the hardware
which generated the enable signal was working — there were
definitely ENABLE pulses getting to the I/O device. Little
else was obvious as a result of a lot of testing.
The problem was that there were two major mistakes in my
design. Neither of the problems was found by test equipment
but rather by long hours looking at the CPU board schematic
and the Z-80 and 6800 timing diagrams.
First, the schematic related problem. Remember that I had
said earlier that I thought my 6502 CPU board and hence
the I/O board were “S-100 compatible.” This wasn’t true.
The key discrepency was in failing to remember that the
S-100 bus latches SINP and SOUT until the next I/O or
memory cycle. That meant that the Z-80 was enabling the
I/O devices long after they should have been in order to
satisfy the 6800 timing.
The obvious cure was to find an unlatched signal. Ob-
viously, the signal I needed was IORQ itself which unfortu-
nately does not appear on the S-100 bus. Since I had
already departed from the ideal by using RFSH, the use of
IORQ (routed to bus pin 63) did not seem out of place. After
all the objective was to make it work, not necessarily be
“S-100 compatible” (whatever that really means). That
changed the logic to
ENABLE = RFSH + IORQ (8)
and the hardware to the configuration shown in Figure 7.
Much to my chagrin this new approach did not work.
Now, the timing diagrams became all important. Although I
mentioned earlier that the CS inputs could be coincident
with ENABLE, I had failed to consider the R/W, RS0, and
RSI inputs. These must be stable about 1 80 nsec (130 nsec
for R/W) prior to the leading edge of ENABLE.
While for a 6800/6502 CPU that is no problem, the
same cannot be said for the Z-80 (or the 8080 for that mat-
ter). A glance back to Figure 3 reveals why the Z-80 cannot
directly satisfy the 6800 I/O device timing. While no
num erical time d elays are shown in Figure 3, it is clear that
WR, from w hich PWR is d erived, transitions essentially co-
incident with IORQ. IORQ is, of course, what I had most re-
cently used to generate ENABLE. Note, there is no such
pr oble m during read operations as long as R/W is the same
as WR. It will be at the READ level all the time, at least until
a write I/O operation comes along. Note, also in Figure 3
that as long as R SO an d RSI are derived from the port ad-
dress, i.e. SINP, PWR or similar signals are not used, they
will meet both read and write cycle timing requirements.
It was apparent that while I could read the I/O devices I
could not write to them. It was at this point that a peculiarity
of the Z-80 came to the rescue. Note again in Figure 3 that
the Z-80 automatically adds a wait state into the middle of all
I/O operations. The net effect of that is that IORQ is true for
something like 1 .250 jisec for a 2 MHz clock. That is over
twice as long as the standard speed 6800 I/O devices re-
quired for ENABLE.
It was obvious that I had to find some way to use some of
that time to solve the write timing problem. Once more
Figure 3 holds the secret. Since IORQ is true shortly after a
leading edge of 0 (the 02 clock), the time until the next lead-
ing edge of 0 could be used to satisfy the set-up time require-
ment. In other words, all I needed to do was delay the lead-
ing edge of ENABLE. The circuit used to generate this de-
layed ENABLE is shown in Figure 8. Note that RFSH is also
delayed, hence, it becomes a pulse one clock cycle long
(about 500 /usee in my case) as opposed to the two clock
cycles it was originally.
Happily, this approach worked. Figures 9 and 1 0 illustrate
the timing relationships between the new ENABLE signal
and the other CPU generated signals. In each figure the
period in which ENA BLE is tru e has been indicated by cross
hatching on either the IORQ or RFSH line.
/ 10 INTERFACE AGE
JUNE 1980
Programming the Z-80
By Rodnay Zaks
Order No. 0-89588-01 3-X
620 pages $ 14.95
Covers the essential aspects of program-
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Z-80 Microprocessor
Programming & Interfacing:
Book 1
By Elizabeth A. Nichols ,
Joseph C. Nichols , and
Peter R. Rony
Order No. 0-672-21610-18
496 pages $12.95
The second of two laboratory-oriented texts,
addresses the interfacing of digital circuits.
8080 Machine Language
Programming For Beginners
By Ron Santore
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104 pages $6.95
This beginners' book will take you step-by-
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A detailed approach to assembly language
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The key question remaining is whether or not extrapola-
tion of these results to other system configurations is pos-
sible. The answer is a clear yes. The actual approach taken
may differ but the general approach is the same — use the
CPU generated signals and the system clock to create the
necessary delays. For example, consider that even though
the 8080 does not automatically generate that valuable extra
wait state during I/O operations, one or more could easily
be generated by the I/O board logic and then used to create
the necessary I/O device timing in conjunction with the 01
or 02 clock. Similarly an “unlatched IORQ” could be
generated using SINP and SOUT again synchronized to the
01 and 02 clocks. And of course a RFSH-like signal could
be synthesized using the M 1 status signal and the clocks.
What to do about a 2.5 MHz or 4 MHz Z-80 is also clear.
For a 2.5 MHz Z-80 the IORQ signal should be delayed but
the RFSH signal should not be. At 2.5 MHz RFSH is
roughly 800 ns long, so the delay would cut it to about 400
ns — just a bit too short. All that means is that the OR should
be after the delaying flip-flop rather than before as was done
for the 2 MHz case.
At 4 MHz things get a bit messy. RFSH is now 500 /usee
so it can still be used directly but IORQ is short. One could,
of course, use one of the higher speed devices that Motorola
and others now market but the premium paid for those
devices may be too steep. Probably the best answer is to add
a wait state for the I/O cycles.
One aspect of all this discussion should be clear by now.
The key to successfully interfacing devices of different fami-
lies is a thorough understanding of the timing needs at both
ends of the interface. In addition, the secret to implementing
that interface is full and complete utilization of the available
signals, especially the system clock. □
112 INTERFACE AGE
CIRCLE INQUIRY NO. 69
JUNE 1980
I made the TRS-80 into a serious computer.
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I 1
□ Please send me the custom questionnaires for the following
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□ Please send me information on the TRS-80 Model I programs at
$99.95 each
□ Please send me information on other Taranto business programs I
j Your name
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Taranto
& ASSOCIATES, INC.
I PO. Box 6073, 4136 Redwood Hwy., San Rafael CA 94903 • (415) 472-2670
I 1
JUNE 1980
CIRCLE INQUIRY NO. 65
INTERFACE AGE 1 13
An Error Correcting Memory
By Terry Dollhoff
INTRODUCTION
The use of a parity detection circuit to detect memory read
errors is becoming popular with the hobbyist seeking more
reliable memory operation. If the hardware can detect an er-
ror in memory, then it can also correct that error. This article
describes the implementation of a single error correcting,
double error detecting memory for the Technico 16-bit
TI9900 based system. The Technico system was chosen to
illustrate the hardware algorithm because error correction is
more efficient with a 1 6-bit data word than with an 8-bit one.
The hardware described here is now in operation with the
9900. A dramatic demonstration of the hardware is to
remove any one memory chip and observe that the software
is unaffected.
MATHEMATICAL OUTLINE
The best place to begin is with a brief summary of the
mathematical development of the error correcting code. It is
not intended as a comprehensive development of error cor-
recting codes, but it is an overview of the specific code used
for one bit error correction, and two bit error detection of a
1 6-bit memory.
The error correcting code used for single error correct
double error detect is called a cyclic code. All cyclic codes
are based upon the concept of a primitive polynomial. The
definition is not really important here; just assume that the
polynomial presented is a primitive one. Now, if P(X) is a
primitive polynomial of degree m, then it can be proved that
a cyclic code produced by the polynomial:
B(X) = (1 +X)*P(X)
is a double error detecting, single error correcting code. We
will discuss later how the polynomial produces a code. In
particular, the code produced by B(X) has the following
properties:
n (total code length) = 2 m - 1
n-k (no. of parity bits) = m + 1
K (no. of information bits) = 2 m - m - 2
If m = 5 is chosen, then B(X) will reproduce a code with the
following properties:
n = 31 bits
n - k = 6 parity bits
k = 25 data bits
This code has the correction properties needed, but it has 25
data bits instead of 1 6. To arrive at a 1 6-bit code we can use a
shortened cyclic code which is based upon the above code. A
shortened cyclic code is one where all unused data bits are as-
sumed to be zero, and it has the same correction properties.
Thus a 1 6-bit code based upon the above code can be defined.
The first step in developing the code is to locate B(X).
Since (1 + X 2 + X 5 ) is a primitive polynomial of degree m = 5,
the definition for B(X) is:
B(X) = (1 +X)(1 +X 2 + X 5 )
= 1 + X + X 2 + X 3 + X 5 + X 6
Notice that the operator “ + ” is the addition operator for a
group of two elements and is actually a binary exdusive-or.
In fact, the above polynomial can be represented as the
following binary number:
B(X) = 11110 11
since;
B(X) = ri+1*X + 1*X 2 + 1*X 3 + 0*X 4 +1*X 5 +1*X 6
If all data words are also represented as a polynomial, say
M(X), then B(X) produces a code by the following equation:
E(X) = B(X)*M(X)
We will not investigate the use of this form of the code be-
cause it has one distinct implementation disadvantage. That
is, all the stored data bits are functions of the input data bits
(not just the parity bits). This means it is more difficult to test
the memory because all bits are altered before being stored.
This problem can be solved by changing the code to a syste-
matic code. Then the data bits are stored unchanged and on-
ly the six parity bits are functions of the data bits. To change
to a systematic code, calculate another polynomial, H(X), as:
H(X) = (X n + 1)/B(X)
or;
H(X) = (X 31 + 1)/(1 +x + x 2 + x 3 + x 5 + :x 6 )
= 1 + X + X 4 + X 6 + X 7 + X 9 + X n +X 12 + X 14 + X 16 +
X 20 + X 23 + X 24 + X 25
/ 14 INTERFACE AGE
JUNE 1980
V n . k , =
h,*V n . 4 for j = 1 to n -k
If the incoming data bits are represented as:
Data = V 6 V 7 . . .V 30
where (V 2 2 to V 30 are zero), the encoded data is:
Encoded = yoViV 2 V 3 ^ 4 ^^y 6 ^ 7 - ^ 2 ^ 22 - • ^ so M
parity data zero
The equations for the parity bits can be derived from H(X)
and are:
k
1
i = 0
where;
H(X) = h.V’
Since we are only interested in storing 1 6 -bit data, V 22 to
V 30 are all assumed to be zero. With this assumption in
mind, the parity equations can be expanded as:
V5 = V 2 i +V20 + V19 + V, 8 + V 16 + V 14 + V 1 o + V7 + V 6
V 4 = V20 + Vt9 + V 1 8 + V 1 7 + V|5 + V 1 3 + V9 + V/6 + V5
V 3 = V 2 i +V 1 9 + V 18 + V 1 7 + V / 16 + V 14 + Vt 2 + \/ 8 + \/5 + \/4
V 2 — V21 +V20 + Vj 8 + Vj7 + V 1 5 + \/ 1 5 + \/i3 + \/ 11 + V7 + V4 + V3
Vi = V 20 + Vi9 + Vi7 + Vi5 + Vj5+Vi4 + V 1 2 + V 6 + V /3 + V 2
Vo = V21 + Vi9 + Vi 8 + Vig + V15 + V/14 + V13 + V11 +V9 + V5 + V2 + Vi
Certain of the parity bits are based upon other parity bits.
This interaction would cause an implementation problem
and the interactions can be removed by expanding the equa-
tions as illustrated below (as a shorthand notation, write 21
for V 21 , etc.).
V 4 = 20+19 + 18 + 17 + 15 + 13 + 9 + 6 +
21 +20 + 19 + 18 + 16 + 14 + 10 + 7 + 6
Since the + operator is an exclusive-or, X + X = 0. There-
fore the above equation can be reduced to:
V 4 = 21+17 + 16 + 15 + 14+13 + 10 + 9 + 7
Expanding the other parity equations in a like manner, we
can calculate the final set of parity equations.
V 5 = 21+20 + 19 + 18 + 16 + 14+10 + 7 + 6
V 4 = 21+17 + 16 + 15 + 14+13 + 10 + 9 + 7
V 3 = 21+20+16 + 15 + 14+13 + 12 + 9 + 8 + 6
V 2 = 21+18 + 16 + 15 + 13 + 12 + 11+10 + 8 + 6
V, = 19 + 18 + 17 + 16 + 15 + 12 + 11+9 + 6
V 0 = 21+20 + 19 + 17 + 15 + 11+8 + 7 + 6
THEORY OF OPERATION
Now that we have a set of parity equations, we can create
an error correction memory. Figure 1 illustrates the basic
memory system operation. During a write operation, the
parity circuit calculates the six parity bits which are then
stored with the original data bits. During a read operation,
the parity circuit calculates a new set of parity bits based upon
the stored data bits. If this newly calculated set of parity bits is
the same as the stored parity bits, there is no data error (or
more than two errors since this code is limited to double er-
ror detection). If the read parity and the stored parity are not
the same, the data or stored parity are in error.
To diagnose the problem, the two sets of parity bits are
exclusive-ored together to produce a new value called the
syndrome. This syndrome is used to correct the error (single
bit error) or to detect an uncorrectable error (two bit error).
Prior to implementing the correction circuit, it must be
determined which syndrome will be produced by each single
bit error. This can be done emperically. If any single bit is in
error, every parity equation involving the errant bit will be re-
versed in value so the syndrome bit will be set. As an exam-
ple, if bit 13 is in error, then parity bits V 4 , V 3 , V 2 are all
altered. Thus the single error syndrome for bit 13 is
(01 1 100). If this syndrome is encountered during a read,
JUNE 1980
INTERFACE AGE 115
SYNDROME
STORED BIT
DATA BIT
(V5V4V3V2V1V0)
V21
D15
111101
V20
D14
101001
V19
D13
100011
V18
D12
100110
V17
Dll
010011
V16
DIO
111110
V15
D9
011111
V14
D8
111000
V13
D7
011100
V12
D6
001110
VII
D5
000111
V10
D4
110100
V9
D3
011010
V8
D2
001101
V7
D1
110001
V6
DO
101111
V5
—
100000
V4
—
010000
V3
—
001000
V2
—
000100
VI
—
000010
VO
—
000001
Figure 2. Error Syndromes.
then bit 13 is in error. To correct that bit, simply reverse it.
Any syndrome noi in the single bit syndrome family indicates
a noncorrectable error. All of the single bit syndromes are
shown in Figure 2.
IMPLEMENTATION
Four of the parity equations include nine terms and are
easily calculated by a 9-bit generator (74280). The other two
have ten terms and require a 9-bit parity generator and an
exclusive-or gate (7486). This circuit is shown in Figure 3.
The syndrome is calculated by exclusive-or of the stored
parity (called P 0 to P 5 ) with the new one (called V 0 to V 5 ).
This value is used to address an error correction PROM
which will yield C,= 1 if bit Dj is in error. This is shown in
Figure 4. A disable corrections capability is provided by one
of the unused address lines. It is important that the PROM
have a fast access time. We found the TI74S470 perfect for
this application.
+ 5V
Figure 4. Syndrome Calculation and Decode.
Figure 5 shows the actual error correction. Just exclusive-
or the output of the error correction PROM with the memory
data. An uncorrected error will be indicated byC 15 = C 14 =1
or any other two bits since it is a single error code.
Figure 6 shows the overall bus control. Only one extra set
of buffers (for the parity bits) is required. The input data buf-
fers are probably needed elsewhere in the system for other
reasons. Note that when the parity is written, the syndrome is
zero since the stored and computed parity are equal. If not
zero, the buffers, memory for parity, or parity gates have failed.
The circuit in Figure 6 is idealized since we have not ad-
dressed generation of dynamic memory refresh or other
specialized memory controls. Its only purpose is to illustrate
the philosophy of the error correcting circuits.
During a write, the CPU data is stored directly in the Data
Memory and the parity is stored in the Parity Memory. Dur-
ing a read, the data from memory is used to calculate a new
parity (V 0 -V 5 ). If the new parity differs from the stored one
(P0-P5), the error bit is corrected by the error correction circuit.
Figure 5. Error Correction.
1 16 INTERFACE ACE
JUNE 1980
Figure 6. Bus Control.
CONCLUSION
Implementation of an error correcting memory requires
the addition of six bits of memory and a few chips of random
logic. The payoff is in terms of increased reliability. A system
with error correcting memory will require fewer service calls
and if a service call is generated for other reasons, the
memory can be brought back to full operation.
As service costs rise and are measured in hundreds of
dollars and memory costs decline, the user of error correc-
tion will increase. To make error correcting more practical,
the semiconductor manufacturers are developing new cir-
cuits to perform the random logic functions. □
BITS
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JUNE 1980
INTERFACE AGE 117
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CALL TOLL FREE 800-243-7428
From Connecticut Or For Assistance. (203) 354-9375 Qgpt
IS5vN[TB0NICSS[«“™e»,„o;
333 Litchfield Road, New Milford. CT 06776
Please send the items checked below:
□ JAWS 16K RAM kit. No. 6416. $199.95 *
r JAWS 16K RAM fully assembled, tested, burned in.
No. 6416W, $229.95 *
□ JAWS 32K RAM kit. No. 6432. (reg. price $329.95).
SPECIAL PRICE $299.95.*
□ JAWS 32K RAM fully assembled, tested, burned in,
No. 6432W, (reg. price $369.95). SPECIAL PRICE
$339.95.*
D JAWS 48K RAM kit. No. 6448, (reg. price $459.95).
SPECIAL PRICE $399.95.*
□ JAWS 48K fully assembled, tested, burned in. No.
6448W. (reg. price $509.95), SPECIAL PRICE
$449.95.*
□ JAWS 64K RAM kit. No. 6464, (reg. price $589.95),
SPECIAL PRICE $499.95 *
C JAWS 64K RAM fully assembled, tested, burned in,
No. 6464W, (reg. price $649.95). SPECIAL PRICE
$559.95 *
□ Expansion kit, JAWS 16K RAM module, to expand
any of the above in 16K blocks up to 64K, No. 16EXP,
$129.95.*
‘All prices plus $2 postage and handling. Connecticut
residents add sales tax.
Total enclosed: $
1 Personal Check □ Money order or Cashiers Check
□ VISA □ MASTER CHARGE (Bank No. . . .
Acct. No. Exp. Date
Signature
Print Name
Address
City
State Zip.
□ Send me more information
50/80 Interface
Mediamix has introduced a line of products
related to interfacing the TRS-80 to the IBM
Model 50 Electronic Typewriter.
These products include a hardware interface for
connecting the Model 50 to the CPU or the Ex-
pansion Interface. The Mediamix 50/80 Inter-
face plugs into the IBM Circuit board, so there’s
no soldering or modifications to the typewriter
required.
Included with the 50/80 is a software driver
program that lets the user LPRINT and LUST
plus access all of the IBM 50’s special coded
functions, like underlining, indenting, tabbing,
numerical column justification and centering.
For details contact Mediamix, P.O. Box 8775,
Universal City, CA 91608, (213) 475-9949.
CIRCLE INQUIRY NO. 121
Small Business Computer Systems
A line of small business computer systems has
been introduced by Irvine, California based Alpha
Micro. The AM series 1011, 1031 and 1051
computers are muti-tasking, multi-user, multi-
processor, time-sharing computers; models span
the range from modest floppy disk systems to sys-
tems utilizing large capacity hard disk drives. The
systems are designed for large scale program-
ming in BASIC and other high level languages.
The AM series of computers offers many
advantages commonly found on mainframe sys-
tems, at a fraction of the cost. The multi-user,
multi-processor capability permits many users on
the system at the same time.
Each system includes a 1 6-bit processor, with
two on-board serial I/O ports and one parallel
I/O port. 64K of dynamic RAM memory is stan-
dard with each system.
For details contact Alpha Micro, 17881 Sky
Park North, Irvine, CA 927 1 4, (7 1 4) 957-1 404.
CIRCLE INQUIRY NO. 122
miniMAS 2
Micro Application Systems announces
miniMAS 2, Z8-based, high-performance, low-
cost CRT family designed for large volume appli-
cations. The miniMAS 2 weighs approximately
20 pounds, measures 14W x 12H x 18D, and
utilizes an external power supply requiring less
than 50 watts.
Standard hardware features include: 12” CRT,
7x9 dot matrix in a 9x13 field displaying all 128
ASCII codes, 24 lines of 39 or 80 characters,
25th line status display, 2 or 4K of memory for 1
or 2-page display, inverse or normal background,
1 6 baud rates for each of I/O and auxiliary ports
and any combination of inverse, half intensity,
blink, doublewide, underscore, and non-display
attributes. Numeric pad, cursor and editing func-
tion keys, and reset key to terminate undesired ac-
tion are standard.
For details contact Micro Application Systems,
Inc., 5575 N. County Rd. 18, Minneapolis, MN
55442, (612) 559-0320.
CIRCLE INQUIRY NO. 123
Statistical Programs
Compucolor Corporation has released a new
series of statistical programs called “Statistics.”
This three-disk series is especially useful for engi-
neering applications.
These diskettes are entitled: Statistics I, Statis-
tics II and Statistics III. Each disk contains five
separate programs stored on a soft disk and
comes complete with documentation.
Common to all three packages is a file manager
program that generates, maintains and displays
files for use by other programs.
For details contact Compucolor Corp., P.O.
Box 569, Norcross, GA 30091.
CIRCLE INQUIRY NO. 124
Process Control Card
The iCON/CPC-85 Process Control Card and
Family, based on the popular 8085 micro-
processor, offers power, performance and lots of
I/O. It is supported with 1 2K or 24K of EPROM/
PROM, up for 4K NMOS or CMOS RAM with
power down and battery back-up provision.
Also included are three 16-bit timer/counters,
two serial RS-232C ports, and 64 memory-
mapped I/O lines: all on an 8 x 7.5 in. card. The
CPC-85 is fully supported with expansion I/O
cards, card cage, software and much more.
For details contact Process Control Inc.. 221 1
S. 48th St.. Suite C. Tempe, AZ 85282, (602)
894-9105, Harry Latterman. Mktg. Manager.
CIRCLE INQUIRY NO. 125
Word Processing System
Spellbinder by California Pacific Computer
Company includes all the features found on com-
petitive high-quality word processing software —
automatic word wrap, print formatting, propor-
tional spacing, screen editing, justification block
text manipulation, insertion, deletion, typeovers.
search and replace, and emphasis/special
character treatment.
Other features include full mailing list/mailing
lable plus sort/merge and text/merge capacity,
and legal numbering.
Spellbinder is available in IBM 8“ single dens-
ity, North Star double density. Micropolis quad
density. Heath WH89, and Cromemco formats
and is written in 8080 assembly language.
For details contact California Pacific Computer
Co.. 2601 Blackburn. Davis, CA 95616.
CIRCLE INQUIRY NO. 127
1 18 INTERFACE AGE
CIRCLE INQUIRY NO. 84
JUNE 1980
Start Computing For Just $129.95 With An
8085-Based Professional Computer Kit—
Explorer /8 5
100% compatible with all 8080A and
8085 software & development tools!
No matter what your future computing plans may
be, Level “ A at $129.95— is your starting point.
Starting at just $129.95 for a Level “A" operating system,
you can now build the exact computer you want. Explorer/ 85
can be your beginner's system, OEM controller, or IBM-
formatted 8" disk small business system. . .yet you're never
forced to spend a penny for a component or feature you don 7
want and you can expand in small, affordable steps!
Now, for just $129.95, you can own the first level of a fully
expandable computer with professional capabilities— a com-
puter which features the advanced Intel 8085 epu, thereby
giving you immediate access to all software and development
tools that exist for both the 8085 and its 8080A predecessor
( they are 100% software compatible )— a computer which
features onboard S-100 bus expansion— plus instant conver-
sion to mass storage disk memory with either 5-1/4” diskettes
or standard IBM-formatted 8” disks.
For just $129.95 (plus the cost of a power supply, keyboard/
terminal and RF modulator, if you don’t have them already),
Explorer/85 lets you begin computing on a significant level. . .
applying the principles discussed in leading computer maga-
zines. . .developing “state of the art” computer solutions for
both the industrial and leisure environment.
Level “A” Specifications
Explorer/85’s Level “A” system features the advanced Intel
8085 epu, an 8355 ROM with 2k deluxe monitor/operating
system, and an 8155 ROM-I/O— all on a single motherboard
with room for RAM/ROM/PROM/EPROM and S-100 ex-
pansion, plus generous prototyping space.
(Level “A” makes a perfect OEM controller for industrial
applications and is available in a special Hex Version which
can be programmed using
the Netronics Hex Keypad/
Display.)
PC Board: glass epoxy, plated
through holes with solder mask
• I/O: provisions for 25-pin
(DB25) connector for terminal
serial I/O, which can also sup-
port a paper tape reader
...provision for 24-pin DIP
socket for hex keyboard/dis-
play. . .cassette tape recorder in-
put .. .cassette tape recorder output. . .cassette tape control
output. . .speaker output... LED output indicator on SOD
(serial output) line. . printer interface (less drivers). . .total of
four 8-bit plus one 6-bit I/O ports ‘Crystal Frequency: 6.144
MHz • Control Switches: reset and user (RST 7.5)
interrupt. . .additional provisions for RST 5.5, 6.5 and TRAP
interrupts onboard • Counter/Timer: programmable, 14-bit
binary • System RAM: 256 bytes located at F800, ideal for
smaller systems and for use as an isolated stack area in
expanded systems. . . RAM expandable to 64k via S-100 bus or
4K on motherboard.
System Monitor (Terminal Version): 2k bytes of deluxe
system monitor ROM located at F000 leaving 0000 free for user
RAM/ROM. Features include tape load with labeling . . .tape
dump with labeling. . .examine/change contents of memory
...insert data, warm start. . examine and change all
registers. . .single step with register display at each break point,
a debugging/training feature. . .go to execution address. ..
move blocks of. memory from one location to another. . .fill
blocks of memory with a constant . . .display blocks of memory
. . automatic baud rate selection . . . variable display line length
control (1-255 characters/line). . .channelized I/O monitor
routine with 8-bit parallel output for high speed printer...
serial console in and console out channel so that monitor can
communicate with I/O ports.
System Monitor (Hex Version): Tape load with labeling. . .
tape dump with labeling. . .examine/change contents of mem-
ory... insert data... warm start .. .examine and change all
Level “ A ” at $ 129.95 is a
complete operating system,
perfect for beginners, hob-
biests, or industrial con-
troller use.
By Nttronics
By Netronics
ASCII/BAUDOT,
registers. . .single step with register display at each break point CTAIJO ALONE
. . .go to execution address. Level “A” in the Hex Version ^ 1 w efc
makes a perfect controller for industrial applications and can
be programmed using the Netronics Hex Keypad/Display.
Hex Keypad /Display.
Level “B” Specifications
— Hex Keypad/Display
Specifications
Calculator type keypad with 24
system defined and 16 user
defined keys. 6 digit calculator
type display which displays full
address plus data as well as
register and status information.
Computer H-|| 95
Terminal 1W
The Netronics ASCII/BAUDOT Computer Terminal Kit is a
microprocessor-controlled, stand alone keyboard/terminal
requring no computer memory or software. It allows the use of
Level“B” provides the S-100 signals plus buffers/drivers to either a 64. or 32 character by 16 line professional display for-
support up to six S-100 bus boards and includes: address
decoding for onboard 4k RAM expansion select -able in
4k blocks. . address decoding for onboard 8k EPROM expan-
sion selectable in 8k blocks. . address and data bus drivers for
onboard expansion. . wait state generator (jumper selectable),
to allow the use of slower memories. . .two separate 5 volt
regulators.
mat with selectable baud rate, RS232-C or 20 ma. output, full
cursor control and 75 ohm composite video output.
The keyboard follows the standard typewriter configuration
and generates the entire 128 character ASCII upper/lower case
set with 96 printable characters. Features include onboard
regulators, selectable parity, shift lock key, alpha lock jumper,
a drive capability of one TTY load, and the ability to mate
Level “C” Specifications directly with almost any computer, including the new Ex-
' nlnrpr / anH PI P nrnHnpfc hv NI#»t rr\nir*c
Explorer/85 with
"C“ card cage.
Level “C” expands Explorer’s
motherboard with a card cage,
allowing you to plug up to six
S-100 cards directly into the
motherboard. Both cage and
*1 cards are neatly contained inside
Explorer’s deluxe steel cabinet.
Level “C” includes a sheet metal superstructure, a 5-card gold
plated S-100 extension PC board which plugs into the mother-
board. Just add required number of S-100 connectors
Level “D” Specifications
Level "D” provides 4k or RAM, power supply regulation,
filtering decoupling components and sockets to expand your
Explorer/85 memory to 4k (plus the original 256 bytes located
in the 8155A). The static RAM can be located anywhere from
0000 to EFFF in 4k blocks.
Level “E” Specifications
Level “E” adds sockets for 8k of EPROM to use the popular
plorer/85 and ELF products by Netronics.
The Computer Terminal requires no I/O mapping and
includes lk of memory, character generator, 2 key rollover,
processor controlled cursor control, parallel ASCII/BAUDOT
to serial conversion and serial to video processing— fully
crystal controlled for superb accuracy. PC boards are the
highest quality glass epoxy for the ultimate in reliability and
long life.
VIDEO DISPLAY SPECIFICATIONS
The heart of the Netronics Computer Terminal is the micro-
processor-controlled Netronics Video Display Board (VID)
which allows the terminal to utilize either a parallel ASCII or
BAUDOT signal source. The VID converts the parallel data to
serial data which is then formatted to either RS232-C or 20 ma.
current loop output, which can be connected to the serial I/O
on your computer or other interface, i.e.. Modem.
When connected to a computer, the computer must echo the
character received. This data is received by the VID which
processes the information, converting to data to video suitable
Intel 2716 or the Tl 2516. It includes all sockets, power supply t0 be displayed on a TV set Tusing an RF modulator) or on a
regulator, heat sink, filtering and decoupling components.
Sockets may also be used for soon to be available RAM IC’s
(allowing for up to 12k of onboard RAM).
Order A Coordinated
Explorer/85 Applications Pak!
Experimenter's Pak (SAVE $12.50)— Buy Level “A” and Hex
Keypad/ Display for $199.90 and get FREE Intel 8085 user’s
manual plus FREE postage & handling!
Student Pak (SAVE $24.45)— Buy Level “A,” ASCII Key-
board/Computer Terminal, and Power Supply for $319.85 and
get FREE RF Modulator plus FREE Intel 8085 user’s manual
plus FREE postage & handling!
Engineering Pak (SAVE $41.00)— Buy Levels “A,” “B,”
“C,” “D,” and “E” with Power Supply, ASCII Keyboard/
Computer Terminal, and six S-100 Bus Connectors for $514.75
and get 10 FREE computer grade cassette tapes plus FREE BAUDOT Character Set .ABCDEFGHIJKLMNOPQ
8085 user’s manual plus FREE postage & handling! RSTUVWXYZ-?:*3$8()., 9 014! 57; 2/68*
Business Pak (SAVE $89.95)-Buy Explorer/85 Levels “A,” Cursor Modes: Home, Backspace^ Horizontal Tab, Line Feed,
video monitor. The VID generates the cursor, horizontal and
vertical sync pulses and performs the housekeeping relative to
which character and where it is to be displayed on the screen.
Video Output: 1.5 P/ Pinto 75 ohm (El A RS-170) • Baud Rate:
110 and 300 ASCII • Outputs: RS232-C or 20 ma. current loop
• ASCII Character Set: 128 printable characters—
• -tTcA 7 ()*♦,- . ✓0123456789: ;<=>?
«*CD€FGHIJWJ»CPtt^
' abedef 9ki jklAftONr5tttwx¥z{!>*|
Vertical Tab, Carriage Return. Two special cursor sequences
are provided for absolute and relative X-Y cursor addressing •
Cursor Control: Erase, End of Line, Erase of Screen, Form
Feed, Delete • Monitor Operation: 50 or 60Hz (jumper
“B,” and "C” (with cabinet). Power Supply, ASCII Key
board/Computer Terminal (with cabinet), 16k RAM, 12”
Video Monitor, North Star 5-1/4” Disk Drive (includes North
Star BASIC) with power supply and cabinet, all for just . . .
$1599.40 and get 10 FREE 5-1/4” minidiskettes ($49.95 value) selectable.
plus FREE 8085 user’s manual plus FREE postage & handling! Continental U S. A. Credit Card Buyers Outside Connecticut
Continental U S. A. Credit Card Buyers Outside Connecticut CALL TOLL FREE 800-243-7428
CALL TOLL FREE 800-243-7428 _ — To Order From Connecticut Or For Technical
J" NBTronTc?R&? L.7T,
I 333 Litchfield Road. New Milford, CT 06676
■ the item c rhorbo W hairs m __ i . . „ - v. : .
Please send the items checked below—
□ Explorer/85 Level “A” Kit (ASCII
Version), $129.95 plus $3 p&h.
□ Explorer/85 Level “A” Kit (Hex
Version), $129.95 plus $3 p&h.
□ 8k Microsoft BASIC on cassette
tape, $64.95 postpaid.
□ 8k Microsoft BASIC in ROM Kit
(requires Levels “B,” “D,” and “E”),
$99.95 plus $2 p&h.
□ Level “B” (S-100) Kit, $49.95 plus
$2 p&h.
□ Level ”C” (S-100 6-card expander)
Kit, $39.95 plus $2 p&h.
□ Level “D” (4k RAM) Kit, $69.95
plus $2 p&h.
□ Level “E” (EPROM/ROM) Kit,
$5.95 plus 504 p&h.
□ Deluxe Steel Cabinet for Explorer/
85, $49.95 plus $3 p&h.
□ ASCII Keyboard/Computer Ter-
minal Kit (features a full 128 character
set, upper & lower case, full cursor con-
trol, 75 ohm video output convertible
to baudot output, selectable baud rate,
RS232-C or 20 ma. I/O, 32 or 64 char-
acter by 16 line formats, and can be
used with either a CRT monitor or a TV
plus $2 p&ii.
□ Deluxe Steel Cabinet for ASCII
Keyboard/Terminal, $19.95 plus $2.50
p&h.
□ Power Supply Kit ( ± 8V @ 5 amps)
in deluxe steel cabinet, $39.95 plus $2
p&h.
□ Gold Plated S-100 Bus Connectors,
$4.85 each, postpaid.
□ RF Modulator Kit (allows you to
use your TV set as a monitor), $8.95
postpaid.
□ 16k RAM Kit (S-100 Board expands
to 64k), $199.95 plus $2 p&h.
□ 32k RAM Kit, $329.95 plus $2 p&h.
□ 48K RAM Kit, $459.95 plus $2 p&h.
□ 64k RAM Kitr$589.95 plus $2 p&h.
□ 16k RAM Expansion Kit (to expand
any of the above up to 64k), $139.95
plus $2 p&h each.
□ Intel 8085 epu User’s Manual, $7.50
postpaid.
□ Special Computer Grade Cassette
Tapes, $1 .90 each or 3 for $5, postpaid.
□ 12” Video Monitor (10 MHz band-
width), $139.95 plus $5 p&h.
□ North Star Double Density Floppy
Disk Kit (One Drive) for Explorer/
85 (includes 3 drive S-100 controller,
To Order From Connecticut Or For Technical
Assistance. Etc Call (203) 354-9375 "
sonalized disk operating system— just
plug it in and you’re up and running!),
$699.95 plus $5 p&h. - -
□ Power Supply Kit for North Star! I
Disk Drive, $39.95 plus $2 p&h.
□ Deluxe Case for North Star Disk! I
Drive, $39.95 plus $2 p&h.
□ Experimenter’s Pak (see above), I I □
$199.90 postpaid.
□ Student Pak (see above), $319,851 | □
postpaid.
□ Engineering Pak (see above), I I □
$514.75 postpaid.
□ Business Pak (see above), $1599.40 1 | □
postpaid.
Total Enclosed $ | I
r* ~~ Assistance, Etc. Call (203) 354-9375
Tl Netronics R&D Ltd., Dept. PE-9
333 Litchfield Road, New Milford, CT 06776
| I Please send the items checked below —
□ Netronics Stand Alone ASCII Keyboard/Compuler ■
Terminal Kit, $149.95 plus $3.00 postage & handling. I
Deluxe Steel Cabinet for Netronics Keyboard/Termi- .
nal In Blue/Black Finish, $19.95 plus $2.50 postage I
and handling.
Video Display Board Kit alone (less keyboard), S89.95 |
plus $3 postage & handling.
12” Video Monitor (10 MHz bandwidth) fully assem- I
bled and tested, $139.95 plus $5 postage and handling. _
RF Modulator Kit (to use your TV set for a monitor), I
$8.95 postpaid.
5 amp Power Supply Kit In Deluxe Steel Cabinet I
(±8VDC @ 5 amps, plus 6-8 VAC), $39.95 plus $2 J
postage & handling.
(Conn. res. add sales tax) By— ■ | Tota l Enclosed (Conn. res. add sales tax) $ -
□ Personal Check □ M.O. /Cashier’s | | —
Check □ Visa □ Master Charge ■ ■ □ Personal Check □ Cashiers Check/Money Order "
( | | □ Visa □ Master Charge (Bank # ) |
(Bank # )
Acct. # _
Signature _
Print
Name
I
I
I
I usea witn either a CRT monitor or a TV
set (if you have an RF modulator),
« $149.95 plus $2.50 p&h. «■' %»•««»•*•** j o-i w wiiuuiki,
■ □ Hex Keypad/Display Kit, $69.95 DOS, and extended BASIC with per- State
Acct. 8
_Exp. Date _
Address .
City.
j | Signature.
I Print
■ Name
Address _
City
_Exp. Date _
_Zip_
II
II
- _ State
□ Send Me Information m mm La mm mmm
I
I
I
I
II
□ Send Me More Information mm J
_Zip
JUNE 1980
CIRCLE INQUIRY NO. 85
INTERFACE ACE 1 19
1/9TH PAGE ADS
ADVERTISING THAT
PAYS FOR ITSELF
If you haven’t tried INTERFACE AGE’s %th page
advertising, you’re missing out on a valuable sell-
ing tool for your products. Examine these unique
advantages that only INTERFACE AGE provides:
AMERICAN NEWSSTAND DISTRIBUTION
The December 1979 magazine will mark the
third Issue of INTERFACE AGE appearing on the
nation’s newsstands. Since the introduction of
INTERFACE AGE on the newsstands the reader
response has been overwhelming. Now is the
time to reach this new buying audience which
continues to remain unduplicated in any other
microcomputer publication.
EUROPEAN NEWSSTAND DISTRIBUTION
The January INTERFACE AGE will be the
premiere issue on the newsstands in Germany
and Austria. If you’re looking to increase your in-
ternational sales, cash in on this lucrative over-
seas market with your %th page advertising.
COST SAVINGS
At $200.00 per insertion, '/ 9 th page advertising
continues to provide you with the lowest cost per
thousand in the microcomputer industry. Think
about it. Where else will you be able to reach
such an audience at only $ 2.00 per thousand?
Reserve your space early to insure the best posi-
tioning for your %th page ad.
64K MEMORY
FOR THE
HEATHKIT H8’
COMPUTER
Assembled
Kit
$750
$650
64K (56K)
615
525
48K
480
400
32K
345
275
16K
Memory Expansion
Kit -
16K $125
PC Board Only -
With Documentation $ 50
Phone for Free Brochure
714/830-2092
‘HEATHKIT and H8 ore Registered Trademarks of the Heath Co.
H — TRIONYX
H ELECTRONICS
BOXM^^5J5AN^^NA^A 92704
SAVE TRS-80
10%, 15% and more on Computers.
PAN AMERICAN ELECTRONICS, INC., A
Radio /hack
Authorized Sales Center
1117 CONWAY MISSION, TX. 78572
TOLL FREE 800/531-7466
Texas & Main No.
512/581-2765
Multi-User S-100 I/O Board
Micromation’s Multi-User S-100 Board
features four RS232 serial ports with full hand-
shaking capability, three programmable timers,
two bus-driving parallel output ports, three parallel
input ports with handshake capability, plus wire
wrap area for custom circuitry.
The four serial RS 232 I/O ports employ indi-
vidual switch-selectable baud rates to 9600 baud.
The four ports employ 8551 UARTs to deliver
full handshaking and full interrupt support. All
UARTs and timers can be interrupt-driven for fast
system operation.
For details contact Micromation, 488 Cowper
St.. Palo Alto. CA 94301, (415) 328-5181.
David Carlick.
CIRCLE INQUIRY NO. 126
Arithmetic Processor Unit
The Model 781 IB by California Computer
Systems is designed to increase the execution
speed of Applesoft II programs as well as to in-
crease the number of math functions available to
the programmer.
The card employs the AMD951 1 APU. It is a
hardware floating point unit powerful enough to
decrease program execution time by up to one
order of magnitude.
For details contact California Computer Sys-
tems, 250 Caribbean Dr.. Sunnyvale. CA 94086.
CIRCLE INQUIRY NO. 128
Thermal Printer for Apple
Silentype™ is an advanced text and graphics
printer for the Apple II. It is a quiet, low-cost
peripheral that will enable Apple II users to print
on paper copies of anything that the computer
can display on a video monitor or television screen.
Instead of a conventional character-printing
hammer mechanism, the printer uses a 7-dot
thick-film printing element to produce 5x7 dot
characters and graphics on standard thermal
paper. It prints up to 80 characters per line on
8/2 inch wide roll-fed paper.
For more information contact Apple Computer,
Inc., 1 0260 Bandley Dr., Cupertino, CA 95051 ,
(408) 996-1010. Jean Richardson.
CIRCLE INQUIRY NO. 129
Expansion Interface for TRS-80
Lobo Drives International announced the addi-
tion of an expansion interface for the Radio Shack
TRS-80 computer. The Model LX80 enhances
system performance by expanding memory stor-
age capacity up to 40 million bytes.
It provides facilities for up to 32K of RAM and
offers a second serial port. A switch permits over-
riding the keyboard ROM for booting in
diagnostics and customized operating systems.
For details contact Lobo Drives Int’l., 935
Camino Del Sur, Goleta, CA 93017, Mike Mock.
CIRCLE INQUIRY NO. 130
Small Business Computer
The BC-5000 from Panasonic is a desk-top
computer which features a one-touch keyboard
and double-sided, double density floppy disk
drives. The unit can be utilized as a small
business computer or intelligent terminal for
distributed data processing.
The unit is well-suited for order entry, inventory
control, billing and a variety of applications which
can benefit from the increased productivity obtain-
ed when using the one-touch keyboard.
For more information contact Panasonic, One
Panasonic Way, Secaucus. NJ 07094.
CIRCLE INQUIRY NO. 131
Touch Screen Digitizer
The Touch Screen Digitizer from TSD Display
Products is designed for use with 12-inch
diagonal CRTs. The Touch Screen provides one
solution for interfacing personnel who have no
computer and data processing experience with a
database that is stored in a computer. It eliminates
the need for keyboards and light pens. The
operator’s attention is constantly focused on the
screen.
For details contact TSD Display Products, Inc.,
35 Orville Dr., Bohemia, NY 11716.
CIRCLE INQUIRY NO. 132
120 INTERFACE ACE
JUNE 1980
Disk Sort/Merge System
A disk sort/merge system “DSM” is available
for both the TRS Mod-1 and Mod-ll. DSM is a
self-contained system written in machine
language ready for immediate, use.
DSM sorts large multiple diskette files on a
minimum one drive Mod-ll or two drive Mod-1
disk system; physically rearranges all records;
sorts random files created by BASIC, including
sub-records spanning sectors; sorts on one or
more fields in ascending or descending order. It
also provides optional output field deletion, rear-
rangement, and padding.
DSM is available from Racet Computes, 702
Palmdale, Orange. CA 92665, (7 1 4) 637-5016.
CIRCLE INQUIRY NO. 133
Industrial X-Y Digitizer
The Digi-Pad single-unit digitizer tablet
measures 1.7 inches high, has no adjustments,
requires no preventive maintenance and all elec-
tronics are built into the base of the tablet.
Designed for applications requiring the conver-
sion of graphic data into digital form, Digi-Pad
has applications in computer aided design, entry
of menu data, analysis of statistical data and more.
Contact GTCO Corp., 1055 First St., Rock-
ville. MD 20850, (301) 279-9550.
CIRCLE INQUIRY NO. 134
Instant Processor Su/itcher
Dynatech Data Systems has available a front
end processor (FEP) switching system that pro-
vides both network cost savings and increased
reliability. This system allows a single spare pro-
cessor to serve as a backup for multiple on-line
processors, and has the ability to switch all chan-
nels from a failed processor to the spare processor.
The system consists of a series of multi-channel
A/B fallback switches with the spare FEP chained
to the B positions on each switcher. A remote
control panel with interlock circuitry provides in-
stant switching while preventing more than one
set of communications lines from, being con-
nected to the spare FEP simultaneously.
Patching access to every channel permits indi-
vidual channel reconfiguration and non-interrupt-
ing monitor/signal breakout. Operation is con-
trolled by pushbuttons with a keyswitch for system
security.
Contact Dynatech Data Systems, 7644 Dyna-
tech Ct., Springfield. VA 22153, (301)
279-9550.
CIRCLE INQUIRY NO. 135
Microcomputer Printer Interface
The l/OMaster S-100 Interface Board from
MicroPro allows flexible use of either lower cost
letter-quality printers and/or high speed line
printers within the same microcomputer con-
figuration.
Combining four boards in one, l/OMaster
features two each serial and parallel ports as well
as an eight level interrupt control and dual interval
timer circuitry. To insure that keystrokes and
transmitted communication data are not lost dur-
ing task switching operations, l/OMaster’s two
8251 -based serial ports each have built-in
32-character FIFO buffers. All l/OMaster options
are DIP switch selectable.
For details contact MicroPro International
Corp., 1299 Fourth St., San Rafael. CA 94901,
(415) 457-8990.
CIRCLE INQUIRY NO. 136
Parallel/Serial Converter
The PSC/4000. offered by The Standard
Register Company, is an easy-to-use, solid state
microprocessor-based unit. Both interfaces are
programmable. In addition, data can be edited,
reformatted, etc. by the unit prior to output.
The PSC/4000 interfaces a variety of quanti-
tative measuring devices— scales, counters, etc.—
with mini and microcomputers, CRTs, Tele-
typewriters and serial printers.
For details contact The Standard Register Co..
P.O. Box 1167. Dayton, OH 45401.
CIRCLE INQUIRY NO. 138
Treasure Hunt Software Game
CASTLE, a fantasy simulation game in which
the player searches for treasure in a magical
world, is available in North Star disk BASIC (ver-
sion 6 or later). The game provides detailed
descriptions of the locations, objects and situa-
tions encountered by the adventurer, and accepts
English-like commands from a vocabulary of over
1 50 words.
CASTLE requires a system with 32 K bytes of
memory, and a single or double density North
Star disk drive. For more information contact
International Computing and Robotics, 4920
Harmony Way, San Jose, CA 95130.
CIRCLE INQUIRY NO. 137
Wafti/i a
# # #
Your Computer Specialists
HEWLETT
PACKARD
[apple computer
Authorized Dealer
HP-85 Starting $3250.00
• Extended Basic Language
• Advance Graphics
• CRT Built-In Display
• Magnetic Tape Cartridge for Storage
• High Reliability
• Whisper Quiet Printer
HP-97 : 584.00
HP-67 299.00
HP-41 C 295.00
HP-4 1C Printer 385.00
HP-41 C Card Reader 215.00
HP-41C Memory Module 45.00
FREE $200 APPLESOFT CARD with the purchase
of Apple II 16K.
Apple II 16K 1195.00
Apple II Accessories:
Disk II with Controller 535.00
Disk II without Controller 455.00
Apple Clock Card 249.00
Integer Card 180.00
*Leedex 12" Monitor 140.00
::! AI0 Serial & Parallel Card 175.00
: CAT Modem 199.00
*ALF Apple Music Card 239.00
•Independent Manufacturers
alpha
micro
SALES — SERVICE — SOFTWARE
Medical Packages
Accounts Receivable
Accounts Payable— General Ledger
Order Entry — Inventory
Texas Instruments
TI-99/4 Home Computer
• Powerful TI-BASIC
• Up to 72K total memory capacity.
• Outstanding graphic, music and sound
capabilities.
• 13" color monitor included.
• Revolutionary Solid State Speech ™
Synthesizer is optional.
'yiafitk’d, One. 515 DAVIS ST., EVANSTON, ILL. 60201 869-6140
Hours: Mon. - Fri. 8:30 AM - 7 PM
Sat. 9 AM • 6 PM
JUNE 1980
CIRCLE INQUIRY NO. 83
INTERFACE ACE 121
The Business “Dream” Machine?
By David R. Fuller & Harold Henrich
Lazor Systems, Inc.
1050 E. Duane Avenue, Sunnyvale, CA 94086
Although the typical small business system is designed to
serve a single user performing a single task, even the small-
est business or district office outgrows single-minded cap-
ability. The system may have been geared to accounting, but
someone wants word processing. Why not use it for inven-
tory control, production scheduling, or management
analysis? As the range of applications and the number of
users proliferate, the system cannot handle the increased load.
Lazor Systems, Sunnyvale, CA, has developed a system
that solves this problem in two ways. First, the basic system
can perform multiple tasks concurrent with serving multiple
users and stations. Secondly, the system, designed in a
modular fashion, allows for extensive growth in capability at
minimum cost.
The Lazor is an advanced multi-bus multi-processor small
business system that collects, analyzes, decodes, executes
and records multi-channel information at differing through-
put rates. While one 1 6-bit processor serves as the master
CPU, one or more 16-bit I/O processors can be added to
handle multiple input/output operations simultaneously.
Parallel execution by multiple processors is accomplished by
task partitioning and resource allocation.
The Lazor can be used as a master CPU supporting up to
1 6 terminals or as a district office front-end processor com-
municating with a central IBM host via a communications
controller.
Each processor in the network handles two or more of the
five basic functions:
•Task allocation and resource management
•Information processing
•Information concentration and temporary storage
•Local input/output and hardware control
•Remote input/output and communications
Functional organization of the master modules, on the
Lazor Advanced Multibus, each with its own high speed buf-
fer memory, minimizes bus contention allowing effective
122 INTERFACE AGE
JUNE 1980
addressing and aggregate data transfer rate of two megabytes
per second.
INPUT/OUTPUT PROCESSORS
The I/O processor, in conjunction with the I/O controller,
is designed for optimum performance of I/O operations.
The main processor sets up the I/O task in the main
memory and notifies the I/O processor to start execution,
then returns to application execution. The I/O processor ini-
tiates operation by directly addressing the requested device
and giving it a command. The I/O processor controls the
direct memory access (DMA) transfer to buffer memory,
transfers data to and from main memory and devices, handles
all input/output interrupts, and notifies the master processor
when the requested I/O operation is complete.
The I/O processor controls devices with a wide range of
speeds. Multiple devices can interleave transfers of data to
and from memory utilizing the full band-width of the I/O
processor with no degradation. In addition, the I/O pro-
cessor performs error checking on all input/output opera-
tions, retries errors, informs the task requesting the I/O
operation of any non-recoverable errors, and at user option,
keeps a log of errors on a disk data set.
This frees the main processor for task management and
execution of application programs, increasing total
throughput.
INTERRUPTS
The system eliminates the need for high overhead polling
techniques via three classes of interrupts:
warning, invalid address, storage protect violation, divide ex-
ception, double bit error and single cycle.
Class 2 supervisor call interrupts are programmed instruc-
tions under user control to call supervisor routines.
Class 3 I/O interrupts are software maskable and serviced
by the I/O processor using a double indirect vectoring
scheme. This sets a pointer to any of the unique device para-
meters and automatically branches to a common or unique
service routine.
Programmable priority at the control and device levels per-
mit the supervisor program to define or dynamically change the
interrupt priority level of any device. For example, the main
operator console is a priority level 1 , but when another termi-
nal needs real time processing, device priority can be changed
to level 1 , and the main console switched to a lower priority.
There are three ways to mask interrupts. Processor level
masking masks all I/O interrupts. Control level masking
masks I/O on particular priority levels, and device masking
masks a particular device. This gives the Lazor excellent con-
trol of its available resources.
MLX OPERATING SYSTEM
Lazor MLX is an interrupt drive, multi-task operating
system designed to operate with the system architecture to
provide:
•Task management
•Access methods
•Resource management
•Class 1: Non-maskable
•Class 2: Supervisor call
•Class 3: I/O interrupts
Class 1 interrupts are non-maskable to immediately alert
the system to error or exception conditions such as power fail
The task manager schedules tasks for up to 1 6 concurrent
users. Its unique run time monitor and priority scheme provides
dynamic priority switching, at specified intervals, to guarantee
timely application completion. Log-on services are also pro-
vided to prevent unauthorized access to the system.
JUNE 1980
INTERFACE ACE 123
AITOS BREAKS
THE MICRO
BARRIER.
Yesterday, microcomputer meant micro
performance. Once you outgrew it, you had to step
up to a mini. Which meant a big step up in price.
Today, there’s the new Altos ACS8000-6 single-
board microcomputer system.
It’s the first system for the OEM, small business-
man and personal user, that offers minicomputer
performance and minicomputer storage capacities—
at a microcomputer price.
MULTI-USER, WINCHESTER STORAGE,
FLOPPY BACK UP: $14,260.
The new Altos ACS8000-6 is a highly advanced
Z80* based microcomputer system with high-speed
RAM, floppy disk and Winchester hard-
disk controllers, DMA, six serial and
two parallel I/O ports and the AMD
9511 floating point processor all on
a single board. A typical four-user
system configuration with two
megabytes of Shugart floppy
and 29.0 megabytes of Shugart
Winchester storage, including
CPU and 208K bytes of RAM,
costs only $14,260— com-
pared to $30,000 or more for
a similar minicomputer system.
And that adds up to mini
performance at less than half
the cost!
MULTI-USER EXECUTIVE
SUPPORTS FOUR
INDEPENDENT USERS
RUNNING CP/M**
COMPATIBLE PROGRAMS.
compatible programs in any of six popular lan-
guages: BASIC, FORTRAN, COBOL, PASCAL, APL,
C, and a large assortment of additional business
application packages. MP/M is compatible with both
the 1.4 and 2.0 versions of Digital Research’s
CP/M, which means programs based on either
version can run under MP/M without modification.
With MP/M at the helm, your Altos
ACS8000-6 system can support up to four simul-
taneous users with 48K bytes of RAM each plus
58 megabytes of Winchester storage and 4 mega-
bytes of floppy back up. And that adds up to the
first microcomputer to give you the power and
performance of a minicomputer.
SINGLE-USER, HARD-DISK
SYSTEMS START AT $9450.
The Altos ACS8000-6
series. It’s a barrier breaker
in every sense. Our entry-
level, single-user, hard-disc
system with floppy back
up is priced under $10,000
and even our 4-user CP/M
model is available for
under $12,000. And all
configurations are easily
upgraded. For specific
details about pricing or
performance, call or write:
Altos Computer Systems,
2360 Bering Drive, San Jose, CA
(408) 946-6700. TELEX 171562 ALTOS SNA
This revolutionary new microcomputer system
features the MP/M** Multi-User Executive software
program that’s unique in two ways. It includes a
multi-user CP/M capability and the ability to handle
Winchester- type hard disks. The advanced Z80
operating program supports four independent CP/M
(ALlCU]
COMPUTER SYSTEMS
CIRCLE INQUIRY NO. 3
The MLX access methods provide the user with three high
level disk access methods. The Indexed Sequential Access
Method (ISAM) allows the user to access disk resident data
by a key record identifier. Relative record access allows ran-
dom access simply by specifying record number. Sequential
access provides access to records in a sequential manner
beginning with the first record in a file. In addition, password
verification is provided to protect user data sets from
unauthorized access.
The resource manager controls the system’s resources by
providing memory management, timer services, and in-
put/output device allocation. Dynamic allocation and
deallocation of memory, as well as memory partitioning by
task, are provided by the memory management routines.
The resource manager’s timer routines provide accurate
time of day for time stamping applications and messages. It
also provides the task manager with its requested time inter-
vals for priority switching.
The input/output control routines assign physical I/O de-
vices to logical I/O names allowing individual applications to
be independent of particular I/O configurations.
SYSTEM CONFIGURATION
Two system series are available: the economical flexible
disk-based E-series and the cartridge disk-based S-series.
The basic Lazor is a 2.4 megabyte flexible disk computer
system with a 16-bit CPU, 64K bytes of dynamic RAM
memory with ECC, one flexible diskette controller, and one
Winchester disk controller, eight serial interface ports, two
1 .2 megabyte flexible diskette drives, and a 1 6 position back
panel allowing space for expansion.
When the user needs more capability, he can upgrade to a
higher model that adds an I/O processor, 64K bytes of addi-
tional memory, a second flexible diskette controller (one for
each drive), and two parallel interfaces. If the user needs still
more capability, he can move to a unit that adds a 20 mega-
byte Winchester drive and a ninth serial interface. Upgrades
are via plug-in additions.
The S-series begins with the entry-level 32 megabyte cart-
ridge disk computer system. The basic system includes the
16-bit CPU, 128K bytes of dynamic RAM memory with
ECC, a cartridge disk controller, eight serial interfaces, a 32
megabyte cartridge disk subsystem with 1 6 megabytes of re-
movable storage and 1 6 megabytes of fixed storage, and a
20 position back panel for expansion.
One model adds an I/O processor, two parallel interfaces,
a ninth serial interface, an additional 32 megabytes of fixed
disk storage for a total of 64 megabytes. It adds still more
capability by adding a second 16-bit CPU, another 128K
memory, and an additonal 32K megabytes of fixed disk
storage to bring the total storage capacity to 96 megabytes.
Again, the upgrades are made without changing the basic
system hardware or software.
Each model can be configured to meet specific application
requirements. For example, additional I/O controllers pro-
vide for large terminal networks. Parallel interfaces provide
the necessary data rates for complex graphics. Disk drives,
removable or fixed, can be added in various increments to
satisfy applications requiring more storage capacity.
The system will support memory expansion to one megabyte,
up to four double density flexible diskette drives, up to 1 6 local
or remote operator terminals, and multiple printers. With op-
tional communications support, the system can handle bisync
and async data communications protocols and includes a
teletype adapter, providing voltage level compatibility with
EIA RS232 interfaces.
As with other systems, the user can select from a variety of
output devices. Lazor offers interfacing for letter quality
daisywheel printers, matrix printers (operating under serial or
parallel), high speed line printers and printer/plotters.
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/26 INTERFACE ACE
CIRCLE INQUIRY NO. 76
JUNE 1980
PERIPHERALS
•Flexible disk drive (double density, double sided,
1 .2 megabyte)
• 1 40 cps matrix printer (serial interface)
•150 cps matrix printer (parallel interface)
•300 Ipm printer (parallel interface)
•45 cps letter-quality printer
•CRT intelligent terminal
•Winchester disk (20 megabytes)
•Cartridge disk subsystem (32 megabytes, 16 mega-
bytes, fixed; 1 6 megabytes, removable)
•Cartridge disk subsystem (64 megabytes, 48 mega-
bytes, fixed; 1 6 megabytes, removable)
•Cartridge disk subsystem (96 megabytes, 70 mega-
bytes, fixed; 16 megabytes, removable)
SOFTWARE
Lazor MLX multi-level executive operating system
Lazor BASIC compiler
Lazor COBOL compiler
Applications programs
General ledger
Accounts payable
Accounts receivable
Payroll with cost accounting
Order entry with inventory control
Text editor
Word processing
RELIABILITY
Modular design and high-level large-scale integration offer
improved reliability through reduction in the number of com-
ponents and interconnections. Wiring between printed cir-
cuit boards has been eliminated by plugging all boards Into a
common bus back panel. Logic handles worst case timing
and environmental conditions.
A power-fail interrupt protects against failures. When input
line voltage drops below required levels, the system detects
the failure and sends a “power warning interrupt” to the
main processor. The active data files are immediately written
in disk storage.
MEMORY ERROR DETECTION
When an application accesses a memory address that ex-
ceeds memory capacity, in most conventional mini and
micro-based systems, the user is not notified. New data is
either written over existing data in other memory locations or
simply lost. In Lazor, the memory notifies the main CPU and
operator that a program has attempted to access a location
outside of memory boundaries and was unsuccessful.
Memory-write protection is a standard feature in all sys-
tems. The Lazor operating system provides each user with a
protected area of memory, especially valuable when shared
by multiple users.
Error Check and Correction (ECC) minimizes system fail-
ures. ECC will detect all single, double, and some multiple
bit errors and correct all single-bit errors.
DIAGNOSTICS
Diagnostics are run each time the system is powered-on or
system reset is depressed for initialization. Malfunctions are
detected by the sequence-driven master test module and dis-
played on the system console. Modular board design simpli-
fies isolation of system failures.
SECURITY
Lazor offers both software and hardware security keys. Sys-
tem reset and power-on are controlled by a key lock device. □
North Star Horizon/Hard Disk
Timesharing Computer systems
by
micro mike’s, me.
★ ★★★★★
Micro Mike's interrupt-driven, bank switching timesharing is a natural evolutionary progression of the North Star
Horizon computer s foresightful engineering Taking advantage of the standard on-board features of the Horizon.
TIMESHAVER.™ Micro Mike's timesharing/hard disk operating system, allows as many as seven users, each
with 32K to 56K RAM. running different programs simultaneously in North Star BASIC or through CP/M* 2.0. a
variety of programs and languages. As many as jour 26 megabyte (formatted) hard disk units can provide 104
million characters (formatted) of lightning-quick external memory storage, working in conjunction with the
Horizon's double density/quad capacity W minifloppy drives.
In stock:
Complete North Star Horizon timesharing/ hard disk computer systems, including: Zenith Z19 intelligent CRTs
(as many as seven per timesharing system). Shugart 26 megabyte (formatted) sealed-media. Winchester-
type hard disk units (as many as four per system)
Printers:
NEC Spinwriter. Texas instruments Tl 810 and Tl 820. I0S-440 Paper Tiger
Mjcro Mike s has written a comprehensive selection of business application programs in North Star BASIC
using a defined set of Common SUBroutmes (CSUBI
Call or write for descriptive literature
micro mike’s, inc.
r\ 905 South Buchanan
o Amarillo, Texas 79101 ‘U.S.A.*
Telephone: (806) 372-3633
making technology uncomplicated . . .tor people
*CP/M is a registered trademark of Digital Research.
Copyright 1980 Micro Mike's. Incorporated All Rights Reserved
CIRCLE INQUIRY NO. 79
Buy By Mail and Save!
COMPUTERS
INTERTEC SuperBrain®
32 K RAM $2995 . . . $2495
64 K RAM $3345 . . . $2695
NORTH 3TAR Horizon® 1
32 K Kit, List $1999 . $1579
32 K Assembled $2695 $2149
Horizon 2
32 K DD, Kit, $2399 . $1885
32 K DD, Assm. $3095 $2439
32 K QD, Kit $2779 . $2359
32 K QD, Assm. $3595 $2859
CROMEMCO
System 3, 64 K, $6990 . $5479
System 2, 64K, $3990 . $3179
Z-2, List $995 $ 829
VECTOR MZ, $4313 $3439
System B, List $5463 $4359
TI-99/4, List $1150 $985
ALTAR I® 400, List $630 $489
800 List $1080 $839
DISK SYSTEMS
THINKER TOYS®
Discus 2D, $1149 $ 939
Discus 2 + 2, $1549.... $1288
PRIIMTERS/TERMINALS
ANADEX DP-8000 . . $799
T.l. 810 $1575
CENTRONICS 730 1 $739
PAPER TIGER IDS-440 $849
with graphics option . . $949
INTERTUBE II, $995 . $729
PERKIN-ELMER
Bantam 550 $789
SOROC120 $745
TELEVIDEO 912 . . $789
Most items in stock for immediate delivery, factory-sealed cartons, with full factory
warranty. N.Y.S. residents add appropriate sales tax. Prices do not include shipping.
VISA and Master Charge add 3%. COD orders require 25% deposit. Prices subject
to change and offers subject to withdrawal without notice.
Computers Wholesale
P.O. Box 144
Camillus, NY 13031
(315)472-2582
JUNE 1980
CIRCLE INQUIRY NO. 82
INTERFACE ACE 127
BASIC For the Home
Computer
By Bob Albrecht , LeRoy
Finkel, and Jerald R. Brown
Order No. 0-471-03204-2
336 pages $6.95
Learn how to read, write and understand
BASIC, including applications and games
for the hobbyiest or for anyone who wants
to use small computers in home, school or
office
32 BASIC Programs for the
TRS-80
By Tom Rug g and
Phil Feldman
Order No. 0-918398-27-4
290 pages $15.95
Now that you've bought yourself a TRS-80
computer, what do you do with it? You will
.find the answer to that and many more
questions in this book. Each of the 32 chap-
ters fully documents a different program.
The authors explain how to make simple
modifications, and if you have a good work-
ing knowledge of BASIC, you can devise
and implement your own program changes
Valuable to both the noive and "old hand"
Atari BASIC
By Bob Albrecht Leroy
Finkel, and Jerald R. Brown
Order No. 0-471-06496-3
$5.95
Learn to read, write, and understand BASIC-
all in a self-intructional format that requires
no special math or science background or
previous experience with a computer. Sup-
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ing magazines; contains numerous appli-
cations and games.
from Books
BASIC Computer Programs
for the Home
By Charles D. Sternberg
Order No. 0-8104-5154-9
330 pages $8. 95
A comprehensive book of practical home
application programs that will be helpful to
both the novice and the experienced own-
er in increasing the usefulness of all home
computers. Each program is documented
with a description of its functions and
operation, a listing in BASIC, a symbol ta-
ble, sample data, and one or more output
samples.
Some Common BASIC
Programs
By Lon Poole and
Mary Borchers
Order No. 0-931988-06-3
220 pages $12.50
Program listings and documentation for 76
short programs covering financial, mathe-
matical, statistical, and general interest
applications.
Instant BASIC
By Jerald R. Brown
Order No. 0-918398-21-5
159 pages $9.95
For the microcomputer enthusiast or the
user of DEC'S BASIC plus language, here is
an "active participation" workbook design-
ed to use with your home computer. It's an
easy, painless way to learn BASIC.
BASIC 2nd Edition
By Bob Albrecht LeRoy
Finkel and Jerald Brown
Order No. 0-471-03500-9
3i25 Pages $5.95
Revised and updated to make it simpler
than ever to learn BASIC without the need
for special math or science background.
Shows how to use the computer as a tool in
any field from education to the humanities.
Microsoft BASIC
By Ken Knecht
Order No. 0-918398-23-1
225 pages $9.95
Illustrates concepts presented in such a
way that commands valid at each succeed-
ing level of BASIC can be easily used and
understood. By starting with the simplest
and most commonly used commands and
then progressing on to more complex BAS-
IC, the author illustrates how the more
powerful versions of the language can save
valuable programming time and effort.
128 INTERFACE ACE
JUNE 1980
la Basic
Books
DATA
DYNAMICS
TECHNOLOGY
has them all S
Microprocessor BASICS
Edited By Michael Elphick
Order No. 0-8104-5763-6
224 pages $11.95
Aimed at the design engineer, seperate sec-
tions are devoted to each of the popular
microprocessors available. Each section
also discusses one available model, explain-
ing its advantages, disadvantages, architec-
ture, and capabilities.
Computer Dictionary
By Donald Spencer
Order No. 0-89218-038-2
160 pages $5.95
This current and comprehensive dictionary
contains about 2500 words, phrases, and
acronyms used in connection with comput-
ers. The keynote of this book is clarity- with-
out sacrifice of authority and definitional
precision. All definitions are simple, and
stand as independent units of explanation.
This book was written for all those who, in
their work or in their studies, become invol-
ved with computer technology.
The Semiconductor
Memory Book
By Intel Marketing
Communications
Order No. 0-471-03567-X
524 pages $14.95
A complete and extensive collection of
semiconductor memory application and
specification information complied by one
of the world's largest suppliers of memories
and microprocessors.
Microprocessor Interfacing
Techniques
By Austin Lesea, Rod nay Zaks
Order No. 0-89588-029- 6
464 pages $15.95
Microprocessor interfacing is no longer an
art It is a set of techniques, and in some
cases, just a set of components. This book
introduces basic interfacing concepts, and
presents in detail, implementation tech-
niques for both hardware and software. It
covers the essential peripherals, from key-
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buses and introduces basic troubleshooting
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Microcomputer Primer
By Mitchell Waite and
Michael Pardee
Order No. 0-672-21653-1
368 pages $11.95
Build your knowledge and appreciation of
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Covers the most recent advances in micro-
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Computers & Programming
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By Donald D. Spencer
Order No. 0-672-20950-0
288 pages $12.95
Written for the engineer or scientist, this
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works, and how it can be used to the best
advantage. It discusses various types of
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Qcmputero And
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JUNE 1980
INTERFACE AGE 129
Try this for an afternoon’s entertainment: Walk into a com-
puter factory, whip out a simple-looking 1 5-line BASIC pro-
gram, and ask to run it on its most cherished product. While
keying it in, mention that you intend to publish the results in
a national magazine, along with the best performances of a
dozen or so of their most honored competitors. If that
doesn’t immediately result in rapid escort to the nearest exit,
you will find yourself in the center of plenty of attention from
more apprehensive-looking executives than those assembled
for the last IRS audit.
We have taken part in that scenario quite a few times in the
past several months, and have learned a lot about bench-
marking as an art. In its simplest form, a benchmark is a task
that can be run on different computer systems to compare
the performance of each. Ideally, the task should be one that
is meaningful to the intended application of the computer in
your business. Unfortunately, that’s usually possible only to a
very small degree. It would be enlightening to run a
100-employee payroll on two different computer systems
(using identical programs) and compare the results; but that
would be a complicated undertaking and would involve
neutralizing all of the irrelevant variables that might obscure
the outcome.
For our purposes, we have simplified the test, admittedly at
the expense of compromising the meaningfulness of the
result. Our benchmark task is a simple BASIC program that
utilizes two nested FOR/NEXT loops to “discover” all of the
prime numbers up to 1 000. The program is so simple it can
easily be adapted to run on all BASIC variants, and can be
translated into other languages with little difficulty — even on
a programmable pocket calculator. The only performance
criteria we are interested in is speed of execution. This can be
measured without using precision equipment, since a typical
run will take ten minutes or so. We are indebted to Mike
Simmons, inventor of the HEX29, who first showed it to us
during a visit to his laboratory.
Some of the computer factory experts have told us it’s a
dumb program that doesn’t do a very good job of computing
prime numbers. It exercises but a fraction of the large reper-
tory of capabilities featured by any decent computer, so it
tends to favor the simple languages at the expense of those
that otherwise might be far more capable in other respects.
And finally, spitting out prime numbers is a scant test of a
computer as a meaningful addition to society.
All of that is true, of course, but we have developed a fond-
ness for our adopted program, and will continue to use it as* a
test of one small aspect of a computer’s worth. Speed, after
all, is what computing is all about. The beleaguered pur-
chaser has precious little help in quantifying the differences
amongst the current cornucopia of offerings. While far from
being the ultimate test of processing speed, we think that
printing “997” (the last prime less than 1 000) in under four
minutes says more about a system’s capability than quoting
the clock rate of the fastest quartz crystal in the machine.
Table 1 shows the results we have gathered so far — from
the giant time-sharing engine of a large university’s com-
Table 1.
Benchmark Performance Data
COMPUTER SYSTEM
PROCESSOR
SOFTWARE
BENCHMARK
MANUFACTURER
SYSTEM
TYPE
BITS
SPEED
OPER SYS
LANGUAGE
RUN TIME
Digital Equipment
PDP-10
n/a
36
n/a
TOPS-10
BASIC
65 sec
Digital Microsystems
HEX29
2900
16
6 MHz
HOST
HBASIC +
143 sec
Alpha Micro
AM-100/T
WWD16
16
3 MHz
AMOS 4.3A
AlphaBASIC
317 sec
Alpha Micro
AM-100
WD16
16
2 MHz
AMOS 4.3A
AlphaBASIC
573 sec
Technico
SS-16
9900
16
3 MHz
DOS
Super BASIC 3.0
585 sec
Ohio Scientific
C4-P
6502
8
2 MHz
OS65D 3.2
Level 1 BASIC
680 sec
Radio Shack
TRS-80 Model II
Z80
8
4 MHz
TRSDOS 1.1.2
Level III BASIC
955 sec
Apple
II PLUS
6502
8
2 MHz
DOS 3.2
Applesoft II BASIC
960 sec
Rexon
RX30
8086
16
5 MHz
RECAP
Business BASIC
1020 sec
Ohio Scientific
C3-C
6502
8
1 MHz
OS65D
Level 1 BASIC
1346 sec
ISC
Compucolor 8051
8080
8
n/a
DOS
BASIC 8001
1375 sec
Hewlett-Packard
HP-85
Prop
8
n/a
n/a
BASIC
1380 sec
Basic/Four
600
8080
8
n/a
n/a
BASIC
1404 sec
Micro V
Microstar 1
8085
8
3 MHz
StarDOS
StarDOS BASIC
1438 sec
Zilog
MCZ-1/70
Z80
8
4 MHz
RIO
Zilog BASIC
1864 sec
Radio Shack
TRS-80 Model 1
Z80
8
2 MHz
TRSDOS
Level II BASIC
1928 sec
130 INTERFACE AGE
JUNE 1980
puter sciences school to the most-widely produced computer
in the history of the world: the Radio Shack TRS-80. We
have included all of the configuration information we could
pin down, as there can be significant differences between dif-
ferent versions of an operating system, for example. The
chart only shows the results of testing we have performed
personally. Others have run the benchmark on a variety of
other equipment, but since we weren’t there to witness the
test conditions, we opted to leave the data out of the table, in-
teresting as it was.
Try it yourself, and share the results with us. Use any tricks
you know to speed up the program execution (multiple state-
ment lines, integer variables, etc.), but don’t “improve” on
the basic algorithm itself. A canny programmer at an Ohio
Scientific store knocked 1 0% off the execution time by sub-
stituting variables for line numbers in this manner:
125 LET XI = 0
126 LET X2 = 230
180 IF L = XI THEN X2
That trick doesn’t strike us as being a normal programming
technique, so we didn’t allow it in our chart, even though it
rates an A + for comprehension of his BASIC interpreter’s
inner workings.
Include the actual listing of the program, along with all per-
tinent information regarding operating system version, brand
of language, etc. If enough readers send in results, we will
tabulate them for publication in a future issue. We would par-
ticularly like to share with you data on any runs on large
mainframe computer systems. (If it’s a time-sharing
machine, make several runs during off-peak times and keep
the best one.) It would also be interesting to see how different
operating systems and/or languages compare, using the
same hardware.
The Association of Computer Users (P.O. Box 8003,
Boulder, CO 80301 ) is a non-profit organization that carries
benchmarking to a high art. For $150 per year, you can
subscribe to Benchmark Report, which shows the results of
some in-depth testing on a variety of business computer
systems. Their benchmarks are broken down into speed tests
(CPU and I/O intensive), real life problems (scien-
tific/engineering and accounts receivable) and ease of use
(number of keystrokes required for text editing). They seem
to have covered all of the important areas except, perhaps,
prime number crunching. □ — TF
Program follows
LISTING 1 — Prime Number Cruncher
If the terminal doesn’t supply an automatic carriage
return/line feed at the right-hand edge, line 230 will
cause the display to “stick” after printing only the
first few primes.
lOO REM INTERFACE AGE's benchmark program to
110 REM 'discover 7 the first 1000 prime numbers
120 REM
130 PRINT "Start ins t "
140 FOR N = 1 TO 1000
150 FOR K = 2 TO 500
160 LET M = N/K
170 LET L =* INT(M)
180 IF L = 0 THEN 230
190 IF L = 1 THEN 220
200 IF M > L THEN 220
210 IF M = L THEN 240
220 NEXT K
230 PRINT N i
240 NEXT N
250 PRINT CHR*<7)
260 PRINT "Finished."
270 END
JUNE 1980
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SOFTWARE SECTION
SOFTWARE APPLICATION
A BREAK Service Routine
for a KIM-1 with a Teletype
By Ken Wetzel
Frequently a program requires debugging before it oper-
ates as intended. The use of software interrupts, or break-
points, are recognized debugging aids; to this end, many
microcomputer monitors include breakpoint routines. The
KIM-1 monitor lacks this capability. The program presented
here is for use with a KIM-1 and a TTY terminal. It allows the
listing of the contents of the internal registers of the 6502
microprocessor unit (MPU) whenever the MPU encounters
a breakpoint in the execution of a program. This break ser-
vice routine returns control to the KIM monitor to permit
user intervention before continuing with program execution.
In using a break service routine it is necessary to replace
an opcode within the user’s program with the breakpoint.
Specifically, for the 6502 the opcode for break (BRK) is
‘00’. Replacing an opcode with the opcode for break is often
called ‘patching’ a breakpoint. Monitors, on some other
microcomputers have break service routines that automatic-
ally patch the breakpoint while saving the original opcode,
and then automatically restore the original opcode during
execution. Convenient as they are, such routines are limited
in the number of breakpoints they can support.
The program I have written requires patching breakpoints
into a program and restoring the original opcodes, both
manually. Although I was primarily concerned with having a
short enough routine to fit in the available RAM that begins
at address 1 780, the routine also has the advantage of serv :
ing a limitless number of breakpoints. What I have attempted
to optimize, however, is the format for printing the MPU
contents on the TTY. The format is shown in figure 1 .
02C5 X:39 Y*02 A:61 SlFF N: 1 V*0 >1 Btl DM ItO Zll C * 1
Figure 1. Break Service print out format.
The break service routine has the TTY do a carriage return
and a line feed, print the address of the breakpoint encount-
ered, and then print the contents of the X and Y index regis-
ters, the accumulator, the stack pointer, and each flag with its
status. The undefined 6502 flag is identified with a blank. As
soon as the status of the carry flag is printed, control of the
KIM-1 is returned to the user via the usual command keys.
Examples of this are included in this article.
The use of this break service routine is straightforward. If a
program is demonstrating questionable responses, merely
change the opcode at the suspect location to 00. When the pro-
gram is run again, the breakpoint will activate the TTY listing of
the MPU registers, provided that execution reaches the break-
point. I find that a liberal number of breakpoints is desirable
when the errant program demonstrates confusing execution.
Since the breakpoints are inserted and removed manually,
it is quite helpful to patch a breakpoint over an NOP, even
though a BRK can be patched over any opcode in RAM.
With this method it is not necessary to repeatedly patch a
breakpoint and restore the original opcode to repeatedly exe-
cute the program. The debugging ease which results from
patching over an NOP makes it very desirable to include
them in strategic locations during the initial stages of pro-
gram development.
The following example will help to illustrate the breakpoint
service operation. Figures 2 and 3 show a sample program
before and after patching two breakpoints. One replaced an
NOP, and the other a BNE. Figure 4 shows the computer
response and operator commands when running the pro-
gram of figure 3. The first line shows the starting address of
the program and the operator’s ‘G ? command to resume
program execution. After the computer finished the second
line, the operator advanced. to the opcode following the BRK
by using the return key. The computer then printed the ad-
dress and opcode on the third line and the operator restarted
program execution with the G key.
0000
18
TEST CLC
Nonsense program to
0001
F8
SED
demonstrate Break Service
0002
A9
39
LDA #
39
A '
0004
AA
REPEAT TAX
0005
69
63
ADC #
63
0007
A8
TAY
0008
49
63
E0R #
63
000A
EA
NOP
Space to patch a breakpoint
000B
24
13
BIT z
DATA
000D
DO
F5
BNE
REPEAT
000F
D8
CLD
Enable KIM TTY routines
0010
4C
64 1C
JMP
CLEAR
Return to monitor
0013
9E
DATA
Figure 2. Sample program before patching break
points.
0000
18 (TEST)
CLC
Nonsense program with
0001
F8
SED
breakpoints patched in
0002
A9 39
LDA #
39
0004
AA REPEAT
TAX
0005
69 63
ADC #
63
0007
A8
TAY
0008
49 63
E0R #
63
000A
00
BRK
Breakpoint 000A
000B
24 13
BIT z
DATA
000D
00 F5
BRK
★
Breakpoint 000D
000F
D8
★
0010
4C 64 1C
*
0013
9E DATA
<
* Ambiguious until BRK
at address 000D
is replaced with original opcode.
Figure 3. Sample program with break points.
132 INTERFACE AGE
JUNE 1980
Introducing a whole new school of thought are the new twins of the
microcomputer industry . . . the Model Z80/64 CPU and memory
board and the Model TWO-X single/double density disk controller.
Like degrees and diplomas this new class is an achievement
beyond compare.
The Z80/64, a Z80 processor, runs at a full 4 Mz and
is supplemented with 64K bytes of dynamic RAM with
provisions for vectored interrupts and 2K EPROM, all
on a quality S-100 bus board. The Z80/64 has low
power requirements and full transparent refresh during
unutilized processor time. With CPU and memory on
the same board, timing problems and bus noise are
eliminated. Who said you can’t teach an old system
new tricks?
I
The TWO-X, double/single density disk drive controller,
handles four 8" or three 5" single or double headed
disk drives, and operates single/double density auto-
matically. Transfering files between densities, operating
at 2 or 4 Mz, the TWO-X includes a RS232 Serial port.
There’s a hardware 2708 PROM on board and the soft-
ware is all ready to go, configured to run without a
front panel. It’s a real apple polisher. ;
To send your system to the head of it’s class, put these boards in our new “Cool” mainframe, the Model 2018 desk
or rack mount cabinets . . . they’re in a class by themselves.
So if you are ready to stand above the crowd, call the “Coolest” distributors in the country, CMC MARKETING, or
see them at your local retail computer store.
V
10611 Harwin, Suite 406, Houston, Texas 77036 • (713)995-4960* TWX: 910-881-7155 TELEX: 762072
© 1 979 CMC Marketing Corp.
JUNE 1980
CIRCLE INQUIRY NO. 74
INTERFACE ACE 133
SOFTWARE APPLICATION
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CIRCLE INQUIRY NO. 75
mniAi A COMPUTER
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Model 44 — Automobile trip computer with cruise control.
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Prices & availability subject to change without prior notice.
0000 18 G
000A X : 39 Y*02 A*61
000B 24 G
0000 X l 39 Y *02 A*61
000E F5
000D DO G
S *FF NtO Vtl *1 8*1
SlFF NlO VIO *1 B 1 1
on no zto cn
Dtl 1*0 Zll C:l DO.
Figure 4. Computer response and operator com-
mands for program in figure 3.
Note that this procedure is used when the breakpoint be-
ing serviced is patched over an NOP. The fourth through
sixth lines show the operation when a breakpoint is patched
over an actual opcode and the operator desires to continue
execution after the break service is finished. The fourth line
shows that after the computer printed the status of the C flag,
the operator typed in the original opcode, in this case ‘DO’,
and depressed the period key to enter the opcode into memory.
The computer responded by printing the following memory
location with its contents, in this case ‘000E F5’. Now it is
necessary to backup to the desired opcode by using the LINE
FEED key on the TTY. The last line of figure 4 shows the ad-
dress of the replaced opcode, the replaced opcode, and the
‘G’ the operator typed to resume program execution.
1780
08
BRKSRV
CLD
1781
85
F3
SAVE
STA
z
F3
1783
68
PLA
1784
85
FI
STA
z
FI
1786
68
PLA
1787
38
SEC
1788
E9
02
SBC
#
02
178A
85
EF
STA
z
EF
178C
85
FA
STA
z
FA
178E
68
PLA
178F
E9
00
SBC
#
00
1791
85
F0
STA
z
F0
1793
85
FB
STA
z
FB
1795
84
F4
STY
z
F4
1797
86
F5
STX
z
F5
1799
BA
TSX
179A
86
F2
STX
z
F2
179C
20
2F
IE
PPC
JSR
CRLF
179F
20
IE
IE
JSR
PRTPNT
17A2
A2
0B
LDX
#
0B
17A4
20
CA
17
PREG
JSR
PSUB
17A7
B5
EA
LDA
zX
EA
17A9
20
3B
IE
JSR
PRTBYT
17AC
CA
DEX
17AD
E0
07
CPX
#
07
17AF
DO
F3
BNE
PREG
17B1
A5
FI
LDA
z
FI
17B3
85
F7
STA
z
F7
17B5
20
CA
17
PFLAG
JSR
PSUB
17B8
A9
30
LDA
#
30
17BA
06
F7
ASL
z
F7
17BC
69
00
ADC
#
00
17BE
20
A0
IE
JSR
0UTCH
17C1
CA
DEX
17C2
10
FI
BPL
PFLAG
17C4
20
9E
IE
JSR
0UTSP
17C7
4C
64
1C
JMP
CLEAR
17CA
20
9E
IE
PSUB
JSR
0UTSP
17C0
BD
D9
17
LDA
ex
TABLE
17D0
20
A0
IE
JSR
0UTCH
1703
A9
3A
LDA
#
3A
17D5
20
A0
IE
JSR
0UTCH
17D8
60
RTS
17D9 43 TABLE
17DA 5A
17DB 49
17DC 44
1700 42
170E 20
17DF 56
17E0 4E
17E1 53
17E2 41
17E3 59
17E4 58
Enable TTY monitor routines*
Save MPU registers
Correct Program Counter address
Car. ret. & line feed (KIM subr)
Print contents of FA & FB (KIM)
Point to end of lookup table
Print lookup table & ' : '
Get saved register
Print A as 2 hex characters (KIM)
Move pointer
Finished with registers?
No: do another ' PREG *
Yes: get status flags and
save in temp
Print lookup table &
ASCII zero
Flag to ASCII char conversion
Print A as ASCII character (KIM)
Finished? No: next flag
Yes: print a space (KIM)
and return control to KIM
Print a space (KIM)
Get ASCII char from table
Print a character (KIM)
ASCII colon
Print a colon (KIM)
ASCII C
* Z
" I
• D
" B
" SPACE
" V
M N
" S
M A
" Y
M X
* The KIM monitor routines for the TTY don't all execute correctly
if the 'O' flag is set.
Figure 5. Break Service Routine
134 INTERFACE ACE
CIRCLE INQUIRY NO. 88
JUNE 1980
SOFTWARE SECTION
r
The All New
In order to use this break service routine, it is necessary to
store the starting address, 1780, in the IRQ vector location
17FE and 17FF of the KIM RAM. However, if an interrupt
system using the IRQ is being operated, it is necessary to
store the interrupt service routine starting address in the IRQ
vector. Then include in the interrupt service routine a test of
the B flag and a jump to 1 780 when it’s set. An example for
implementing this appears in the 6502 Programming Manual.
The documentation for this program appears in figure 5.
The save registers part of the program is essentially the same
as the SAVE routine at location 1C00 in the KIM monitor.
The one difference is that the address stored into locations
00FA and 00FB is adjusted by subtracting 2 from the
numbers stored when the Program Counter is pushed on the
stack. That is necessary to make those registers point to the
address of the breakpoint being serviced. (It seems the 6502
adds 2 to the Program Counter before it realizes that the
BRK command is actually an interrupt.)
The break service program also uses an unconventional
return to the KIM monitor. The usual return address of 1 C4F
causes the TTY to print the ‘KIM’ and the address of the break-
point with ‘00’ on two extra lines. I considered this an unneces-
sary waste of paper and time. After a bit of trial and error, I
found that a jump to address 1 C64 eliminates this difficulty.
In using the program I have found two distinct applications
for it. The first is its use to test registers and flags to verify
proper program operation or to locate a malfunction. The
second use is the one I actually employ most often: I keep
the service routine at location 1 780, and fill all unused RAM
with BRKs (opcode 00). Then almost any mistake I make is
immediately caught. Destroyed programs are virtually a thing
of the past.
0000
A2 7F
BS BF
LDX #
7F
Set pointer to END
0002
B5 10
MOVE
LDA zX
10
Get byte to be moved
0004
90 80
17
STA 0X
BRKSRV
Store in 1780-17FF RAM
0007
CA
DEX
Decrement pointer
0008
10 F8
BPL
MOVE
Finished? No: do another 'MOVE'
000A
A9 00
BRKFIL LDA #
00
Yes: clear A
oooc
EA
NOP
000D
4C E5
17
JMP
CLRRAM
Jump to the moved BRKFIL program
0010
D8
BRKSRV
First line of BRKSRV
0074
58
Last line of BRKSRV
0075
8D 00
16
CLRRAM STA 0
AL.AH
Store 00 in RAM address AL, AH
0078
EE E6
17
INC 0
AL
Next RAM address
007B
00 F8
BNE
CLRRAM
This page full? No: do 'CLRRAM'
0070
CE E7
17
DEC 0
AH
Yes: next page
0080
10 F3
BPL
CLRRAM
Last page? No: do 'CLRRAM'
0082
4C 22
1C
JMP
RST
Yes: jump to monitor
0085
00
Bytes to be moved to KIM RAM:
0086
00
0087
01
for the tape interface
0088
00
0089
00
008A
00
for the NMI vector
008B
1C
008C
4F
for the RST vector
008D
1C
008E
80
for the IRQ vector
008F
17
EN0
Figure 6. Program to load break services and fill
RAM with BRKs.
The program of figure 6 is the one I use to load my break
service routine and to fill RAM with BRKs. It’s very easy to
use since the tape load routine returns with 0000, the start-
ing address of this program. Just load the program from
tape, depress the G key, and then the RUB OUT key. The
RUB OUT key is necessary since this program destroys the
information stored during initialization of the TTY, and there-
fore must be re-initialized.
The KIM-1 break service provides a useful routine that fits
in a limited amount of memory. □
SYSTEM B/Q
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V J
JUNE 1980
CIRCLE INQUIRY NO. 87
INTERFACE ACE 135
SOFTWARE SECTION
SOFTWARE REVIEW
INTRODUCTION
The availability of modern computers has changed our
lives in several ways. One of these changes affects the way
we prepare written documents. A business letter may be dic-
tated to a secretary who will type the letter in its final form.
Reports may be handled differently because they are longer.
In this case, the author will prepare an outline followed by a
handwritten rough draft. The next version will then be typed
from the rough draft.
If major changes are necessary, the report can be cut apart
and taped back together in its new form. A boiler-plate sec-
tion, describing the capabilities of the company, may be
appended to the end of the report. If there are many
changes, then the entire report may have to be retyped.
COMPUTERIZED TEXT FORMATTING
Report preparation is considerably simplified if a text-for-
matting computer program is available. With this approach,
the author’s handwritten draft is typed into a computer under
control of the system editor. Format commands are embedded
in the text at this time. A separate, text-formatting program is
then invoked to generate the finished document. This final
result appears at the line printer or is stored on disk as a
separate file.
Major rearrangement of the text is easily accomplished if
the system editor has a block-move command. The report
never has to be retyped.
One text formatter, the Electric Pencil, was reviewed in the
August 1978 issue of INTERFACE AGE. This program
combines an editor of sorts with a text formatter. It cannot,
however, be used with a serial video console since it requires
a memory-mapped video screen.
There are several text formatters available for the CP/M
operating system. One of these is Word Star by Micropro.
Another formatter, Tex (reviewed in the May 1979 issue of
INTERFACE AGE) is provided by Digital Research. A
similar text formatter program, Textwriter, is available from
Organic Software of Livermore, CA. The same program is
available from Micropro under the name of Tex-Writer.
There are separate versions available to use on CP/M,
Micropolis and North Star operating systems. A TRS-80
CP/M version is also provided. At least 32K bytes of
memory should be available.
Textwriter is similar to Tex. Both can convert an existing
work file that is stored on disk into a finished file. The work
file is previously prepared with the system editor. Textwriter
can operate on either of two file formats. In the standard for-
mat, each line of the work file is terminated with a carriage-
return, line-feed combination. But Textwriter can also format
files that were prepared with Electric Pencil. The finished file
can be printed during the formatting process or it can be saved
as a separate disk file to be printed at a later time.
THE WORK FILE
The work file is created from the rough-draft manuscript by
using the system editor. The default file-name extension is
TEX for the Digital Research Tex formatter. But since there
is no default extension name for Textwriter, one might
choose the name TXT. This will be an easy way to
distinguish Tex work files from Textwriter work files. This
distinction is necessary since the two programs use different
formatting commands.
The text is entered directly into the work file without regard
to form. If a word is too long to fit at the end of a line, it is
placed on the next line. It is not split with a hyphen.
Textwriter accepts about 50 formatting commands. Some
of these are automatically set to their default values, but they
may be redefined within the text. The general commands for
text formatters typically begin with a decimal point. Text-
writer is different in that the commands begin with an excla-
136 INTERFACE ACE
JUNE 1980
SOFTWARE SECTION
SOFTWARE REVIEW
mation point. If you don’t like the exclamation point, how-
ever, you can change it to something else with the COM-
CHAR command. The statement:
ICOMCHAR “ ”
will change the command character from the exclamation
point to a decimal point.
There will generally be a block of formatting commands at
the top of the work file that are used to set the desired values.
The manuscript for this present article was formatted with
Textwriter. The following commands were given at the
beginning of the work file:
!margins 10 64
[head 8
[foot 5
[ignore
Feb 1 1 ,80
!tty
[justify
[pagenum 1 3 “B’
[skip 5
[center
Textwriter
An 8080/Z-80 Text-
Review by Alan R. M
Software Editor
[spacing 2
[skip 3
INTRODUCTION
[par 3 0
<margins at columns 10 and 64>
<8 lines at top of page>
<5 lines at bottom of page>
<don’t print next line>
<version>
<fake form feed with line feeds>
<align right column>
<number pages at bottom>
<skip 5 lines>
Output Formatter
iller
<double space>
<paragraph, indent 3>
Additional formatting commands are included within the
text. Some of the more useful commands are:
[par
[literal
[pageifnot 6
[skip 2
[spacing 1
[spacing 2
[left 5
[right 5
[resetmar
[footnote
!* <comment>
Start a new paragraph
Use next section as is
Start a new page if 6 or less lines
are left
Skip 2 lines
Single space the text
Double space the text
Indent left margin 5 spaces
Indent right margin 5 spaces
Reset margin to regular width
Make a footnote of next section
A one-line comment
LONG REPORTS
ASCII files that are larger than about 30K bytes are cumber-
some to deal with. This is especially true if the system editor is
not disk oriented, because, in this case, the entire file must be
loaded into memory at one time. Editors like ED, Word-Master,
EDIT-80, or ED-80 are disk oriented. Consequently, a small
portion of the file can be copied from disk into memory for
editing. Even with this type of editor, it is much more con-
venient to edit a file if it can be entirely loaded into memory.
The work file for a long report or even one chapter of a
book can easily exceed 30K bytes. This size is too large to fit
into memory. The solution, in this case, is simple if Text-
writer is available. The work file is generated as a sequence
of conveniently sized disk files. The last line of each file con-
tains a CHAIN command which gives the name of the next
file in the series. For example, suppose that chapter 4 of a
book were broken up into two parts called:
CHAPT4A.TXT and
CHAPT4B.TXT
The last line of the file CHAPT4A.TXT would be:
[CHAIN “CHAPT4B.TXT”
Chapter 4 can be formatted into a single disk file with the
system command:
A>TW LST : = CHAP4A.TXT
The finished file will appear at the line printer (LST:) and will
include both parts of chapter 4. When the formatter reaches
the end of the file CHAPT4A.TXT, the chain command will
direct it to the file CHAPT4B.TXT. The combined finish file
can alternately be formed into a disk file called CHAP4.PRN
by giving the command:
A>TW CHAP4.PRN = CHAP4A.TXT
Notice that both the destination filename and the source file-
name must be given in the command line. Furthermore,
both filename extensions must be given.
EMBEDDED COMMANDS
Most of the Textwriter commands begin with an exclama-
tion point and appeal on separate lines from the text. In these
cases there is little chance that commands will be confused
with text. There are, However, three Textwriter commands
that could cause problems. These commands do not utilize
the exclamation point. Furthermore, they are embedded
within the regular text rather than being on a separate line.
One of the embedded commands is used to underline a
portion of text. The particular section of the work file is
enclosed with a pair of braces. The finished document will
contain the desired underlining, not the original braces. If
brace symbols are desired in the final text, then the underline
symbols will have to be changed. This is performed with the
UNDERLINE command. After the command:
[UNDERLINE “[]”
appears, then the bracket pairs will define the text to be
underlined instead of the braces. More importantly, the
braces can now appear in the final text.
A similar situation occurs with the tilde and the at-sign.
The tilde is used to indicate a space between two words that
must appear on the same line. Textwriter might break up
the section:
February 28, 1 980
so that the month and day appear at the end of one line and
the year at the beginning of the next. Using a tilde instead of
the spaces will guarantee that the date will be printed entirely
on the same line:
February 28, 1980
The at-sign is used for non-standard tab stops. Both the
tilde and the at-sign cannot appear in the final text unless the
corresponding commands are redefined. For example, the
statements:
[SPACEBAR “\”
[TABCHAR
will change the space character to a backslash and the tab
character to an ampersand.
A powerful feature of Textwriter is the ability to input data
from the console or from a separate disk file during the for-
matting process. With this feature, a standard business letter
JUNE 1980
INTERFACE AGE 137
SAVE PRODUCTS^OR TRS-80
The largest family
of disk drives from
the largest supplier,
drives come
complete with
power supply and
cabinet.
MTI-40 Disk Drive. 35 & 40 track $369
TF-1 Pertec FD200. 40 track, use both sides $389
TF-3 Shugart SA400, 35 track, same as tandy $389
TF-5 MPI B51, 40 track $379
TF-70 Micropolis. 77 track with 195K of storage $639
TDH-1 Dual sided drive, 35 track $499
Max Disk 2: 10 Megabyte (fixed)
Winchester Technology
$5349
i NEW PRODUCTS
16K Memory $66
Modem $179
Expansion Interface 32K $499
AC Isolator $47.95
PRINTERS
DP800 Anadex, 80 column, 112cps $949
LP779 Centronics 779 $1099
LP730 Centronics 730 $950
LP700 Centronics 700 $1395
LP701 Centronics 701 $1759
LP702 Centronics 702 $1995
SPW-1 Spinwriter-NEC $2525
NEW! LINE PRINTER
AniDM Pnnter 80 ' 132 co,< 9 ra Phics
60 LPM with tractors
$599
* DRIVES FOR ANY MICROCOMPUTER *
Does not include power supply & cabinet.
MOD II DISK DRIVES NOW AVAILABLE
Perfec FD200
Pertec FD250 (dual head)
Shugart SA400 (unused)
Shugart SA800
MPI B52 $349 B51
$282
$399
$286
$479
$279
SOFTWARE
Disk Drive Motor Speed Test $19.95
New DOS+ with over 200 modifications and
corrections to TRS-DOS $99
New DO$+ 40 track $110
AJA Word Processor $75
AJA Business Program $250
Racet Infinite Basic $49.95
Disk Drive Alignment Program $109
Radix Data Base Program $99.95
Electric Pencil $150 y
ALL PRICES CASH DISCOUNTED. FREIGHT FOB/FACTORY
Eft
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TECHNOLOGY
INCORPORATED
pparat, Inc
3304 W. MacArthur
Santa Ana, CA 92704
(714) 979-9923
CIRCLE INQUIRY NO. 77
7310 E. Princeton Ave.
Denver, CO 80222
(303) 758-7275
CIRCLE INQUIRY NO. 72
SOFTWARE REVIEW
can be run many times. Each time the letter is printed, the
name and address of a different recipient can be read from
the system console or from a separate disk file.
TABLE OF CONTENTS
Long reports and books need a table of contents. The
Textwriter command CONTENTS is used for this purpose. It
operates in a curious way, however. The title for each section
or subsection must be entered twice, once for the actual en-
try, and once for the table entry. For example, the command
pair might look like this:
[SKIP
[CONTENTS 2 “3.4 Passing Data on the Stack”
3.4 Passing Data on the Stack
!PAR
The number 2 in the CONTENTS line causes the subhead-
ing to be indented two spaces.
The necessary duplication of the heading can be easily
accomplished with the Q-buffer command of the Word-
Master editor. At the end of the report, the CONTENTS
command is given without arguments to force printing of the
actual table of contents. The corresponding chapter num-
bers, if any, and the page numbers are printed opposite the
given headings. A row of dots connects the heading to the
page number.
GENERATION OF AN INDEX
The preparation of an index for a book or a long report can
be tedious. The global-search command of the system editor
can be used on the finished file, if it was saved on disk during
the formatting step. But a better way is to use the INDEX
command of Textwriter. Each index entry or subentry is de-
fined with a command such as:
[INDEX “stack”
An index entry can be followed by a comma and a subentry:
INDEX “flag, carry”
INDEX “flag, zero”
INDEX “flag, parity”
The main entry is only given once in the resulting index:
flag,
carry, 2-3
parity, 2-5
zero, 2-4, 4-5
Then, a final INDEX command near the end of the docu-
ment will product the complete index.
CONCLUSION
This reviewer has just finished a book on assembly lan-
guage programming. The entire manuscript was written and
edited with Word-Master and formatted with Textwriter. The
task was made easier by some of the unique features of Text-
writer. In particular, the book’s author and title were printed
on the top line of each page. The chapter number or appen-
dix letter and the page number were printed at the bottom of
each page. The CHAIN command was used to combine the
work files of longer chapters into single finished chapters.
One task has not yet been completed. This is the prepara-
tion of an index. I expect that the INDEX command of Text-
writer will greatly simplify this step.D
138 INTERFACE ACE
JUNE 1980
this
publication is
available in
mteroform
University M/iitttIMh 4 Kl w:m
tdt to W
•W ]
Microfilms inn taii r :>u
International
jvfd h t»l «?!•
I
Please send me additional information. University Microfilms
International
Name
Institution
Street
City
State.
-Zip
300 North Zeeb Road
Dept. P.R.
Ann Arbor, Ml 48106
U.S.A.
18 Bedford Row
Dept. P.R.
London, WC1R 4EJ
England
? EDI
START INPUT
* L
F ILE NAME*EC2
*W
OHG 8000H
ORR 2C00H
C IN
EQU 201 OH
DOS
EQU 2028H
LX I SP» 9000H
XRA A
STA POS
TEST*
CALL CIN
CPI 3
JZ DOS
CALL PRINT
JMP TEST
BASIC:
MOV A#E
TABLE
EQU 8200H
LENGTH
SET 208
PKINT «
PUSH H
PUSH D
PUSH B
LX I H# TABLE
ANI 7FH
CPI ODH
JZ RETURN
CPI 20H
JC EXIT
JZ SPACE
MV I C * LENGTH
TLOOP:
CMP M
I NX H
JZ MATCH
DCR C
JNZ TLOOP
JMP EXIT
MATCH! LDA CURNT
MOV B* A
CALL LIFT
CALL INDEX
PLOOPl MOV 4.M
ANI 40H
CNZ LIFT
MOV C » M
CALL MOVE
CALL DROP
I NX H
MOV A»M
RAL
JC PLOOP
MOV A.B
STA CURNT
EXIT! POP B
POP D
POP H
RET
I
SPACE* LX I H.SPCS
INR M
JMP EXIT
l
INDEX! XCHG
LX! H.SPCS
MOV C.M
MV I M.O
I NX H
MOV A.M
ADD C
INR A
MOV M.A
XCHG
MV I E.203Q
MOV A.C
CPI l
CNC HPOS
MOV A.B
ANI 70
ORI 3 50Q
MOV C.A
MOV A.M
ANI 1 OOU
JNZ INSXP
MOV A.C
ANI 370Q
MOV C.A
INSKPl CALL MOVE
MOV A.B
ANI 207G
MOV B.A
MOV A.M
ANI 40H
CZ DROP
RET
>
LIFT! MV I A. BOH
OUT 24
ORA P
MOV B.A
MV I A. 20
CALL DELAV
RET
i
THE DUST WRITER
Continued from Page 68
PROGRAM LISTING
140 INTERFACE ACE
JUNE 1980
DELAY I PUSH B
D LOOP 1 t MV I C * 80
D LOOPS » DCk C
JNZ DL00P2
DCR A
JNZ DL00P1
POP B
rtET
MOVE*
s
DROP:
MOVEXt
REVX:
MXLOPt
MOV A *B
SUP c
AN! 77Q
RZ
CALL MOV EX
CALL MOVEY
CALL MOVEX
CALL MOVEY
CALL MOVEX
CALL MOVEY
CALL CNTY
CALL MOVEX
CALL CN TX
JMP MOVE
XhA A
OUl 24
OKA B
HP
MOV B * 4
MV I A * 0
CALL DELAY
RET
MOV A *C
HAL
ANI 80H
MOV E# A
MOV A *B
ANI 70Q
MOV D* A
MOV A»C
ANI 700
SUB D
RZ
JC RE VX
INK E
INK E
INK e
MV I D » 2
MOV A * E
OUT 24
MV I A * 20
CALL DELAY
DCh D
JNZ MXLOP
RET
MOVEY: MOV A # R
ANI 7
MOV D* A
MOV A *C
ANI 7
SUB D
RZ
MOV A * E
X REVY
ADI 8
REVY l
ADI 4
ANI 3740
MOV E * A
OUT 24
MV I A* 14
CALL DELAY
RET
»
CNTXt
MOV A * E
C NSKP :
ANI 3
RZ
DCh A
MV I A* -8
UZ CNSKP
MV I A* 8
ADD B
;
CNTYI
MOV B* A
RET
MOV A* E
CNYSKP*
ANI 12
KZ
SUI 4
MV I A * - 1
UZ CNYSKP
MV I A * 1
ADD b
•
MOV P * A
RET
•
RETURN*
LDA POS
:
CPI i
JC EXIT
MV I E * 20 1 0
CALL HPOS
OUI 24
STA POS
JMP EXIT
HPOSt
MOV D* A
H LOOP 1 t
MV I C * 40
H LOOPS 1
MOV A* E
OUT 24
MV I A* 18
CALL DELAY
DCR C
JNZ HL00P2
DCR D
JNZ HL00P1
RET
5
SPCSt
DB 0
POS*
DB 0
C UHNT *
DB 0
*£
END
?EDT
START INPUT
* L
FILE NAME»TBL
*W
ORG 8200H
ORR 2E00H
TABLE:
DB M § M * 3240*2220* 23 20
DB 2330*2430*2450*2360
DB 21 60*2050*2010*2100
DB 2400
DB "A"#204Q*22*Q
DB 24 4Q *2400*3020*2420
DB #, B M *20*0*2360*2450
DB 2430*2030*2430*2410
DB 2300*2000
DB '*C ,# *34 50 *2360*2160
DB 2050*2010*2100*2300
DB 24 IQ
DB •'D'* * 2060 #2360 #2450
DB 2410*2300*2000
DB M E M * 3400*2000*2060
DB 2460*3330*2030
DB M F M * 206 Q *2460*3330
DB 2030
DB M G M * 3320*2420*2400
DB 2100*2010*2050*2160
DB 2460
DB "H M * 20 *Q * 3460 * 240Q
DB 3030*2430
DB M I M *3100*2 300*3200
DB 2260*3160*23*0
DP '*U M *3010*2100*2300
DP 24 l Q > 24 6Q
DB *• K M * 2060*3460* 2 l 3Q
DP 240Q
DP M L M *3400 * 200 Q * 20 6Q
DB M M M * 20 6Q *2240*2230
DB 2240*2460*2400
DP M N M * 2060*2050 *24 10
DB 2400*2460
DB M 0 M *3010*2050*2160
DB 2360*2450*2410*2300
DB 2100*2010
DB M P M * 2060 *2360*24 50
DB 2440*2330*2030
DB M G M * 3010*2050*2160
DB 2360*2450*2420*2200
DB 2100*2010*3220*2400
DB M h M * 2060 *2360*24 50
DB 2440*2330*2030*2130
DB 240Q
DB M S M * 30 10*2100* 2300
DB 241Q*242Q*233Q*213Q
DB 2040*2050*21*0*2360
DB 245Q
DB '*! M * 3200 *2260*3060
DB 2460 ; ’
DB , *U" *3060*2010*2100
DB 2300 *2410*2460
DB M V M * 3060*2020*22 00
DB 2420*2460
DB "W" * 30*0*2000*2220
DB 2230*2220*2400*2460
DB VX** * 20 IQ# 2450* 24 60
DB 3060*2050*2410*2400
DB "Y"* 3200*2230*2050
DB 206Q* 3460*2450*2230
DB M Z ,# *3060*24*0*2450
DB 2010*2000*2400
DB 0
END
JUNE 1980
INTERFACE AGE 141
MICRO-MARKET
MICRO-MARKET ADS
SELL
YOUR PRODUCTS
A new format has been estab-
lished for the Micro-Market sec-
tion. All ads are now 2 inches
wide by 3 inches deep. Price is
$200. Submit ads with check or
money order to:
INTERFACE AGE Magazine
Micro-Market Ads
P.O. Box 1234
Cerritos, CA 90701
HOW CAN I GROW
B TREES?
ORDER MICRO B +™
• Get fast insertion, retrieval
and deletion of index entries.
• Never need to reorganize
your index; no matter how
often it is updated.
MICRO B+ SOURCE CODE $195
MICRO B + DEMO DISK $25
SHIPPING $2 USA. 15 FOREIGN
Available in 8” format for CBASIC-II
and MICROSOFT Basic Version 5.
2606 Johnson Drive
La|Q ( A II Columbia, Mo 65201
lAIn VVlfl 314-445-3304
Check/ VISA /Mastercharge
Moonshadow Text Formatter for
UCSD Pascal™ Systems
The UCSD PascalTM system contains a
screen-oriented text editor which is convenient,
but which is not suited to word processing. It can-
not underline, paginate automatically, or perform
other essential text-processing functions. The
Moonshadow Text Formatter (MTF) from Merri-
mack Systems solves this problem.
With the Moonshadow Text Formatter, docu-
ments produced with the screen editor are post-
processed to provide these missing functions. It
takes standard Pascal text files, operates on
them, and sends fully formatted text output to the
console display, a printer, or a disk file
Moonshadow Text Formatter provides, in addi-
tion to a full range of formatting functions-, ad-
vanced features including the combination of
files into one document, variables in text (for form
letters), and output character translation.
The Moonshadow Text Formatter is written in
UCSD PascalTM, and is available for North Star
Apple II, LSI-II, and 8080/Z80 systems with IBM
Format 8’ floppy disks.
All this for $125.00 from
Merrimack Systems
POB 5218
Redwood City, CA 94063
(415) 365-6281
California residents should include 6% sales tax.
Also available: North Star Pascal personaliza-
tion for SOL/SOLOS — just transfer three files
and you’re up with Pascal $25.00
Power Supplies
INPUT: t1Sv*c43 83hz
OUTPUT: S vdc 0 25 amps
REGULATION: 0.1% *5 mV
NL FL. £ 0.1% * $mV lor 10%
Inpul change
RIPPLE: 2mV RMS mat.. 20 mV
STABILITY: Typically 10 m V lot
5 volts
@ 25 amps
SURPLUS UNITS IN
LIKE NEW CONDITION
REMOTE SENSING. REMOTE VOLTAGE ADJUSTMENT.
OVERLOAD PROTECTION and OVERVOLTAGE PROTECTION
ALSO AVAILABLE IN 12 VDC «> 13 AMPS *79.00 p*f unit
79."
per unit
HOUSE MARKED
DARLINGTON TRANSISTOR
SPtCIFY s AMPS S5 WATTS
22/44 EDGEBOARD CONNECTOR
TIN SOLDERTAIL .156” x .200"
LARGE QUANTITIES AVAILABLE
SI. 35 each 10 for $12.50
1 V, AMP
FULL
WAVE
BRIDGE
RECTIFIER
REED RELAYS
D.P.S.T. 1200 ohm coll-
ALL CLC<TR<HII<S <ORP.
905 S. Vermont Ave. • Los Angeles. Calif. 90006
DEPT.IF-1 (213)380 8000 TERMS
• Ouantltioa Limited
STORE & WAREHOUSE HOURS .Mm ordertiooo
Mon. • Frl. Saturday * **J* ,S °
9 AH. 5 PM 10 AM- 3 PM .SSSZin
SEND FOR OUR FREE CATALOG Prompt Shipping
GET Paid t
for using your
Computer ^
FUN-' Easy CS3
RUSH COUPON FOR ^
FREE FACTS
SPARE TIME
Send today to — DAR-IA6
31 1 0 Fu Iton Ave, Sacramento CA 95821
KEYCAPS
ENGRAVED
for
Cherry and
Keytronic keyboards
24 Hour Service
ARKAY ENGRAVERS., INC.
2073 Newbridge Road
Bellmore, New York 11710
[ 516 ] 781-9859
SAVE MORE THAN 20%!
NORTH STAR - INTERTUBE
THINKER TOYS - MICROTEK
The smartest computers at the smartest price
Quad & Double Density
LIST ONLY
HORIZON 1-32K-D kit $1,999 $1585
HORIZON-2-32K-D kit 2399 1905
Assembled & tested 2765 2195
HORIZON-2-32K kit QUAD 2799 2225
Assembled & tested 32 1 5 2555
Pascal for North Star on Disk 49
Powerful North Star BASIC FREE
TEI PT 2 1 2 Computer 5 MHz 8000 6250
Thinker Toys DISCUS 2/D. A&T 1149 949
Discus/2 + 2 1 .2 megabytes, A&T 1549 1299
Measurement System Memory. A&T. 4MHz 64K 640
Godbout Memory Call for Price
INTERTUBE II Smart Terminal 995 780
MICROTEK Printer 750 675
ANADEX Printer 995 875
Florida Data Printer. 600 cps. 4300 Call lor Price
MARVELLEN Word Processor Your Best Buy 38
Textwriter III 125
EZ-80 Tutorial. Learn Machine Language 25
PDS for North Star. Better than CP/M 99
Compiler for Horizon Secret Superfast Code 1 00
//)• off software prices with computers
VERBATIM the best Diskettes Box of 1 0 29
Which Computers are best? BROCHURE FREE
North Star documentation refundable w/HRZ 20
AMERICAN SQUARE COMPUTERS
Kivett Dr Jamestown. NC 27282 919-883-1105
Connect your TRS-80 . Apple or ANY
other computer to the phone lines.
USR-330 Originate—
Auto-Answer Modem
0-300 Baud
Stand Alone
RS232
1 Year Warranty
Crystal Controlled
Bell 103/113
• State of the Art LSI circuitry
• 5 stage active filters
FCC certified for direct
connection to phone lines via
standard extension phone jack
Call or write for free literature
U.S. ROBDTICS, INC.
1035 W. LAKE ST.
$339
(312) 733-0497
BUSINESS SOFTWARE
CP/M AND MODEL II COMPATIBLE
NEWLY ENHANCED VERSIONS
MEDICAL MGMT SYSTEM $495
DENTAL MGMT SYSTEM $495
REAL ESTATE MULTI LIST $495
INSURANCE AGENCY MGMT $495
LEGAL TIME ACCOUNTING $495
GENERAL LEDGER $495
ACCOUNTS PAYABLE $495
ACCOUNTS RECEIVABLE $495
PAYROLL PROCESSING $495
INVENTORY MANAGEMENT $495
WORD PROCESSING/NAD $495
DATABASE MANAGEMENT $495
HIGH SPEED UTILITY SORT $300
NEW. LATEST CBASIC-2 $ 99
NEW. LATEST MBASIC 5.1 $300
NEW! MBASIC COMPILER $350
* *CPM 2.0 FOR MODEL II $170
COMPLETE SOFTWARE CATALOG ... 5
COMPLETE HARDWARE GUIDE 5
UN1VAIR, INC. 314-426-1099
10327 LAMBERT INTL AIRPORT
ST. LOUIS, MISSOURI 63145 USA
MASTER CHARGE/VISA CARDS O K.
142 INTERFACE AGE
JUNE 1980
MICPODEX
MONITORS, HIGH resolution B/W-
color Sony, Sharp, Hitachi, S-C, all sizes,
most from stock. Lowest prices. Catalog
$1.00. M-C/Visa. Video Technology, Inc.,
1 4422 N.W. 7 Avenue, Miami, FL 33168,
(305) 688-6618.
WANTED: UTILITY billing package for
TRS-80 Model II running under CP/M or
TRSDOS. Send information and price to:
Edwin Phillips, 928 Davis, New Madrid,
MO 63869.
TRS-80 QUALITY SOFTWARE. Data
base manager/report generator: no user
programming, $69, MOD-II $199. A/R,
$69, MOD-II $149. Inventory, key random
access, $99, MOD-II $149. Word proces-
sor, $49. Mailing list, $59, MOD-II $99.
Manual $5, MOD-II $10. Micro Architect,
96 Dothan St., Arlington, MA 02174.
VIRTUOSO PET. 8/16/32K Commo-
dores play Bach, Beethoven, etc. Music
Box & Allen Animation have 4 programs,
$10 each. Order both for free CB2 connec-
tor. Add $1 shipping. Allen Computer Prod-
ucts, Box 22836B, Livonia, Ml 48151.
WEST GERMAN computer store seeking
vendors for hardware and software. Write
Kleinofen Elektronik, Koelner Str. 49,
D-4000, Duesseldorf 1 , West Germany.
16K-RAM COMPUTER - New per
sonal computer. Limited quantity. $300 off
factory list. Sale price $399.00. First come
basis. Call (312) 382-2192. Write J.H.S.,
515 W. Shadylane, Barrington, IL 60010.
TRS-80 SPEED CONTROL plans -
very simple circuit allows wide range of con-
trol over speed of listing or running pro-
grams. Connect to TRS-80 port, or any
Z-80. $15.00 check to: Golden Circuits,
P.O. Box 404, Golden, CO 80401.
BOWLING SECRETARY for North Star
Most complete package available. Handles
prior or self-establishing averages, blinds,
vacancies. Can input number of games
before handicap becomes official. Keeps 3
places for scratch/handicap high game/,
series/average for both men and women.
Prints weekly league sheet, individual
records and sub report. Only $60. JCS
Computer Systems, 4815 F.M. 2351,
Suite 202, Friendswood, TX 77546.
DOUBLE-SIDED SHUGART 8 ’ floppy
drives with single and double density cap-
ability. Will store up to 1 .2 megabytes per
MICRO INDEX CLASSIFIED
drive. Currently sell for $940 each. Asking
$1600 for the pair. New, in cartons. Dennis
Dickerson, Rt. 1 , One Shannon Valley,
Crowley, TX 76036, (817) 737-1313.
TRS-80 PINBALL game, requires Level-
11 16K. Actual speed assembler program
with flippers, bumpers, rollovers, targets.
$19.95. Grania Software, 16, Jackson
Court, Kanata, Ontario, Canada K2K 1 B7.
TRS-80 EXCHANGE - Used TRS-80s
bought and sold. Level I’s, IPs and
peripherals available with warrantees. For a
quick response, call Roy (203) 669-0726.
MICRODEX is a classified advertising
section available to readers wishing to
buy, sell or trade hardware, software,
peripherals, accessories, etc.
Price is $1 per word, with a 25 word
minimum. The first two words are
printed bold. Additional bold type is $5
per word.
Send ad copy with check or money
order to INTERFACE AGE Magazine,
Dept. M l, 16704 Marquardt Avenue,
Cerritos, CA 90701.
IMMEDIATE DELIVERY — FROM ORANGE MICRO
BASE 2 PRINTER
$ 599 00
FREE!!
RS232 CABLE*
$ 25 u0 Value
HR
TELEVIDEO 912B
$ 769 00
STANDARD FEATURES (partial list)
• Reverse video. Underline, Blinking.
Reduced
• Protected fields. Security Blank fields.
• Block or Conversational modes.
• Editing: Line or Character; Insert/ Delete.
• Tab. Backtab; Columnar tab.
• 14 key numeric pad with return key.
• RS232 Printer Port
OPTIONAL:
• Deluxe Selectric® Keyboard: s 75 00
• 2nd Page Memory: s 80 00
• 11 Special function keys and
8 edit keys: s 70 00
FEATURES:
• 72, 80, 96. 120 or 132 Columns per line.
• Bi-directional, 7 dot matrix, impact.
• Graphics Capability.
• RS232, Centronics®, IEEE-488, 20 ma.
• 60 LPM / Fast feed.
• User Programmable Character Fonts.
• 16 Baud Rates — to 19,200.
• Expanded Characters.
•Tractor Mechanism
OPTIONAL:
• 2K Memory Buffer: s 50 00
•Paper Rack: $ 20°°
Phone orders WELCOME. Same day shipment for VISA and MASTER CHARGE.
VISA I Personal checks require 2 weeks to clear. Add 3% for shipping and handling. CA
residents add 6%. Manufacturer’s warranty included. Prices subject to revision.
Digicom Coupler
ORIGINATE
$ 179 °°
* with initial order of
CRT or Printer
COMPARE QUALITY,
FEATURES & DISCOUNT
Products also available:
Qume, MPI, Lear Siegler, Cables,
System Furniture
CALL OR WRITE FOR CATALOG
CALL ( 714 ) 630-3322
TOLL FREE (800) 854-8275
JUNE 1980
CIRCLE INQUIRY NO. 86
INTERFACE ACE 143
WANT TO BE KING
OF THE HILL?
Treat Yourself Royally with GIMIX
Unique and Incomparable Boards
and Systems . . . DIP-switch Versatility
for use with both SS50 (6800) and
SS50C (6809) Systems (SWTP. etc.)
32K STATIC RAM BOARD
• SS50C Extended Addressing (can be disabled)
• 4 separate 8K blocks
• Low Power 2114L RAMS (2 AMP TYP. for 32K)
• Write Protect
• Fully Socketed for 32K
• Gold Bus Connectors
16K. $ 328.12
24K. .$ 438.14
32K . $ 548.15
16 & 24 K Versions are socketed for 32K and require
only additional 2114S for expansion.
All GIMIX Memory Boards are assembled, burned-in,
and tested at 2MHz.
FACTORY PRIME STATIC RAMS
2114L450 ns. . .$5.90 200 ns . . .. $6.90
4044 450 ns $5.90 250 ns. . ..$6.90
Add $5.00 Handling on Orders Undor $200.00
THE UNIQUE GIMIX
80 x 24 VIDEO BOARD
★ Upper and Lower Case with Descenders
★ Contiguous 8x10 Character Cells
★ Hardware Scrolling
★ X-Y Addressable Hardware Cursor
It is the ONLY Video Board that
gives you Software Control of:
• A programmable RAM Character Generator plus
2 EPROM Character Generators (128 char. ea.).
• Selecting 256 Displayable Characters from 384
available.
• Normal or inverse video, full or reduced intensity,
or combinations of these by both ASCII Code and
Bit 8.
• GHOSTability — multiple boards at the same ad-
dress.
Fully decoded, occupies only 2K of address space
Fully socketed — Gold bus connectors.
Assembled, Burned-in, and Tested at 2MHz.
Deluxe Version $458.76
Without RAM Character Generator . . $398.24
Other Video Boards from $198.71
CLASSY
CHASSIS
• Ferro-resonant Power Supply
• Heavyweight Aluminum Cabinet with fan and pro-
visions for two 5” disk drives.
• 6800/6809 Mother Board, fifteen 50 pin and 8 DIP-
switch addressable 30 pin slots — Gold Plated
Pins. Fully decoded
With Baud Rate Generator on Mother Board . . . $828.19
32K SYSTEM Incomparable Features,
at a Comparable Price! . . $1,594.59
Includes: Chassis, 6800 CPU, 32K RAM Board,
Choice of I/O Card.
16K Version of above $1,374.49
Phone, write, or see your dealer for details and prices on our
broad range of Boards and Systems for the SS50/SS50C bus
and our AC Power Control Products for all computers.
Gimix (5i
1337 W. 37th Place • Chicago, IL 60609
(312) 927-5510 • TWX 910-221-4055
The Company that delivers.
Quality Electronic products since 1975.
GIMIX' and GHOST 1 are Registered Trademarks
of GIMIX Inc.
CIRCLE INQUIRY NO. 31
ADVERTISER INDEX
Info
Info
Inquiry
Number
Page
Inquiry
Number
Page
MANUFACTURERS
1
A.E.I
. . .44
54
RLM Associates
24
2
APF Electronics
. . . .9
55
Racet Computes
39
3
Altos 124-125
*
Rainbow Computing Inc. . .
6
4
Anadex
. . IBC
21
Robotics Press
61
5
Applied Digital Data Systems . . .
...11
56
SWTPC
IFC
6
California Data Corp
. . .42
57
Serendipity Systems
43
7
California Pacific Computer Co. .
. . .25
*
Shugart
. . , . 14-15
8
CAP Electronics
. . .32
58
Sigma International Inc. . . .
28
9
Compumax
. . .96
Plus insert between pages
112 & 113
10
CompuServe
. . .93
59
The Software Store
45
11
Computer Furniture & Accessories
. .10
60,61
Structured Systems Group . .
. . . .16-17
12
Computer Marketing
. . .44
62
Supersoft
35
13
Computer Pathways Unltd., Inc. .
. . .79
63
The Swingline Co
8
14
Computhink
. . .21
64
Sybex
88
15
Compu/Time
. . .64.
65
Taranto & Associates, Inc. .
113
16
Cromemco Inc
. .. . 1
66
Tarbell Electronics
28
*
Cybernetics Inc
. .49
*
TIS
... 64
*
Data Dynamics Technology . . . .
. . .20
67
Thinker Toys
63
Ill, 128-129
68
Ultra-Violet Products, Inc. . .
37
18
Datasmith
. .46
69
United Software of America . .
112
19
Diablo Systems
. . .41
*
University Microfilms
139
20
Digital Graphic Systems
. . .47
70
Vandata
34
22
Discount Software Group
. . .47
71
XComp, Inc
8
23
Dynacomp
. . .31
24
Ecosoft
. . .32
25
Electronic Control Technology ..
. . .34
26
Electronic Specialists, Inc
. . .54
27
Epson of America
7
28
Esmark Inc
. . .18
29
Exidy, Inc
52-53
COMPUTER STORES/SURPLUS STORES
30
FMG Corporation
. . .26
72
Apparat. Inc
138
31
Gimix Inc
.144
*
Beta Computer Devices . . . .
117
32
Graham Dorian
. BC
73
Bits N Bytes
117
33
Hardside
. .29
74
CMC Marketing Corp
133
34
Industrial Micro Systems
. . .75
82
Computers Wholesale
127
35
Infosoft
. . .96
75
Data Discount Center
134
36
Integral Data Systems
. . .69
76
Futra Company
126
37
Integrand
. . .46
77
Microcomputer Technology .
138
38
Intelligent Systems Corp
. . .77
78
MicroMail
131
*
INTERFACE AGE Subscriptions .
. Insert
79
Micro Mike’s, Inc
127
between pages 1 6 & 1 7
80,81
Mini Micro Mart, Inc
3, 12
39
Interlude
. . .65
83
Nabih’s, Inc
121
41
Lobo Drives
. . .27
84,85
Netronics R&D Ltd
.118, 119
42
3M
. . .13
86
Orange Micro
143
43
Charles Mann & Associates ....
. . .30
87
Sunshine Computer Inc
135
*
Measurement Systems & Controls
. .55
88
T & W Communications . . .
134
44
Micah
. . .42
*
All Electronics Corp
142
45
Micro-Ap
. . . 19
*
American Square Computers
142
46
Micro Applications Group
. . .54
*
Arkay Engravers., Inc
142
47
Micro Management Systems ....
. . .33
DAR
142
*
Micropolis
22-23
*
Fair Com
142
48
Microsette Co
. . .30
*
Merrimack Systems
142
49
Mountain Hardware, Inc
. . .73
*
Pan American Electronics . . .
120
50
North Star Computers, Inc
. .59
• *
Trionyx
120
51
Personal Financial Systems
. . .4
*
U.S. Robotics, Inc
142
52
Personal Software
. . . .5
*
Univair, Inc
142
53
Physicians Microcomputer Report .
.91
* Manufacturer requests factory-direct inquiry.
144 INTERFACE ACE
JUNE 1980
Introducing our new Alphanumeric Line Printer:
the Anadex Apple/Sider. Specifically designed
for the Apple Computer Business System,
Apple/Sider provides the 96-characters-per-line
required by AL, AP and GL Software of the
Apple Controller.
Based on the time-proven Anadex Model DP-8000
printer, this new unit (Model DP-8000-AP)
bi-directionally prints the complete 96 ASCII
character set in 96 columns at 134 CPS or
84 LPM nominal throughput.
Standard features include a 1 K character buffer
storage (optional, an additional 2048 character
storage for CRT dump or similar uses), internal
programmable top of form and skip over
perforation controls, double width printing, and
a self test feature which checks all memory
and printing functions.
For complete details and the name of your
nearest dealer, contact us today. Inquiries from
qualified dealers are welcomed.
Apple/Sider features a heavy duty printing
head (100M character life) that can print the
original plus up to 3 copies on paper whose
width can range from under 3 inches to 91/2
inches. Paper can be loaded either through the
rear or through the bottom of the printer.
CIRCLE INQUIRY NO. 4
le Computer compatible Printer
Registered Apple Computer, Inc
ncyioicicu uumpuici, mo.
anadex
apple/sider
NADL$, INC. • 9825 DeSoto Avenue »T;hatsworth, C^ifornia 91311, U.S.A. • Telephone: (213) 998-8010 • TWX 910-494-2761
NADEX, LTD. • Dorna House, ^uiM|£d Road • West End, Woking, Surrey GU24 9PW, EnglamJ • Chobham (099Q&6333.* Telex: 858762»AN/IDEX G
* - ' • 1 * \ * % ...
At any given time, your hardware is
only as useful as the software you insert in it.
So it pays to rely on Graham- Dorian,
the software that gets your micro performing
to its fullest — almost like a mini.
Graham -Dorian, the industry leader,
offers highly detailed and well-documented
programs. All pretested on the job. Each so
comprehensive that it takes little time to
learn to run a program — even for someone
who's never operated a computer before.
Programs are compatible with most
major computers using CP/M disk operating
systems, and come in standard 8" or on
various mini-floppy disks. Each package
contains the software program in INT and
BAS file form plus a user's manual and hard
copy source listing. Graham-Dorian stands
behind dealers with technical advice.
Yes, there's a world of difference in
business software. Graham-Dorian has more
per-package capabilities and more packages.
(With new ones added every few months.)
Medical
Dental
Surveying
Inventory
Payroll
Apartment Management
Construction Job Costing
Accounts Receivable
Accounts Payable
General Ledger
Cash Register
CBASIC-2
Ask your dealer for a demonstration soon.
Graham- Dorian
Software Systems, Inc.
211 North Broadway Wichita. KS 67202 (316) 265-8633
J
CIRCLE INQUIRY NO. 32
Live Music
Archive
Librivox
Free Audio
Metropolitan Museum
Cleveland
Museum of Art
Internet
Arcade
Console Living Room
Open Library
American
Libraries
TV News
Understanding
9/11